diff --git a/.travis.yml b/.travis.yml
index 7d9db245b9..7a47c3d297 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,7 @@ sudo: false
 
 scala:
   - "2.12.11"
-  - "2.13.1"
+  - "2.13.3"
 
 before_install: curl -Ls https://git.io/jabba | bash && . ~/.jabba/jabba.sh
 install: jabba install "adopt@~1.$TRAVIS_JDK.0-0" && jabba use "$_" && java -Xmx32m -version
diff --git a/akka-actor-testkit-typed/src/test/scala/akka/actor/testkit/typed/scaladsl/BehaviorTestKitSpec.scala b/akka-actor-testkit-typed/src/test/scala/akka/actor/testkit/typed/scaladsl/BehaviorTestKitSpec.scala
index ca0c252657..ffb994234f 100644
--- a/akka-actor-testkit-typed/src/test/scala/akka/actor/testkit/typed/scaladsl/BehaviorTestKitSpec.scala
+++ b/akka-actor-testkit-typed/src/test/scala/akka/actor/testkit/typed/scaladsl/BehaviorTestKitSpec.scala
@@ -216,14 +216,14 @@ class BehaviorTestKitSpec extends AnyWordSpec with Matchers with LogCapturing {
       val testkit = BehaviorTestKit[Parent.Command](Parent.init)
       testkit.run(SpawnChildren(2))
       val effects = testkit.retrieveAllEffects()
-      effects should contain only (Spawned(Child.initial, "child0"), Spawned(Child.initial, "child1", Props.empty))
+      effects should contain.only(Spawned(Child.initial, "child0"), Spawned(Child.initial, "child1", Props.empty))
     }
 
     "create children when props specified and record effects" in {
       val testkit = BehaviorTestKit[Parent.Command](Parent.init)
       testkit.run(SpawnChildrenWithProps(2, props))
       val effects = testkit.retrieveAllEffects()
-      effects should contain only (Spawned(Child.initial, "child0", props), Spawned(Child.initial, "child1", props))
+      effects should contain.only(Spawned(Child.initial, "child0", props), Spawned(Child.initial, "child1", props))
     }
   }
 
@@ -316,7 +316,7 @@ class BehaviorTestKitSpec extends AnyWordSpec with Matchers with LogCapturing {
       val d = TestInbox[Done]()
       testkit.run(KillSession(sessionRef, d.ref))
 
-      d.receiveAll shouldBe Seq(Done)
+      d.receiveAll() shouldBe Seq(Done)
       testkit.expectEffectType[Stopped]
     }
 
diff --git a/akka-actor-tests/src/test/scala/akka/actor/ActorConfigurationVerificationSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/ActorConfigurationVerificationSpec.scala
index 7fe616cc61..b596e71dbc 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/ActorConfigurationVerificationSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/ActorConfigurationVerificationSpec.scala
@@ -41,7 +41,7 @@ class ActorConfigurationVerificationSpec
     with BeforeAndAfterEach {
   import ActorConfigurationVerificationSpec._
 
-  override def atStartup: Unit = {
+  override def atStartup(): Unit = {
     system.eventStream.publish(Mute(EventFilter[ConfigurationException]("")))
   }
 
diff --git a/akka-actor-tests/src/test/scala/akka/actor/ActorWithBoundedStashSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/ActorWithBoundedStashSpec.scala
index d8a7cef42d..b0aac54c7c 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/ActorWithBoundedStashSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/ActorWithBoundedStashSpec.scala
@@ -93,7 +93,7 @@ class ActorWithBoundedStashSpec
     with ImplicitSender {
   import ActorWithBoundedStashSpec._
 
-  override def atStartup: Unit = {
+  override def atStartup(): Unit = {
     system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*received dead letter from.*hello.*")))
   }
 
diff --git a/akka-actor-tests/src/test/scala/akka/actor/ExtensionSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/ExtensionSpec.scala
index ca4db9dc01..027e10e8f2 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/ExtensionSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/ExtensionSpec.scala
@@ -34,7 +34,7 @@ object InstanceCountingExtension extends ExtensionId[InstanceCountingExtension]
   override def createExtension(system: ExtendedActorSystem): InstanceCountingExtension = {
     new InstanceCountingExtension
   }
-  override def lookup(): ExtensionId[_ <: Extension] = this
+  override def lookup: ExtensionId[_ <: Extension] = this
 }
 
 class InstanceCountingExtension extends Extension {
diff --git a/akka-actor-tests/src/test/scala/akka/actor/SupervisorHierarchySpec.scala b/akka-actor-tests/src/test/scala/akka/actor/SupervisorHierarchySpec.scala
index c32410749f..ed454c98aa 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/SupervisorHierarchySpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/SupervisorHierarchySpec.scala
@@ -160,7 +160,7 @@ object SupervisorHierarchySpec {
 
     def suspendCount = context.asInstanceOf[ActorCell].mailbox.suspendCount
 
-    override def preStart: Unit = {
+    override def preStart(): Unit = {
       log :+= Event("started", identityHashCode(this))
       listener ! Ready(self)
       val s = size - 1 // subtract myself
@@ -258,7 +258,7 @@ object SupervisorHierarchySpec {
       }
     }
 
-    override def postStop: Unit = {
+    override def postStop(): Unit = {
       if (failed || suspended) {
         listener ! ErrorLog("not resumed (" + failed + ", " + suspended + ")", log)
         val state = stateCache.get(self)
@@ -456,7 +456,7 @@ object SupervisorHierarchySpec {
       throw ActorKilledException("I said I wanted to DIE, dammit!")
     }
 
-    override def postStop: Unit = {
+    override def postStop(): Unit = {
       testActor ! "stressTestStopped"
     }
 
diff --git a/akka-actor-tests/src/test/scala/akka/actor/TypedActorSpec.scala b/akka-actor-tests/src/test/scala/akka/actor/TypedActorSpec.scala
index 5c8bb4970d..77d1c5f411 100644
--- a/akka-actor-tests/src/test/scala/akka/actor/TypedActorSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/actor/TypedActorSpec.scala
@@ -48,9 +48,9 @@ object TypedActorSpec {
 
     def hasNext = items != Nil
 
-    def next: T = {
+    def next(): T = {
       @tailrec
-      def findNext: T = {
+      def findNext(): T = {
         val currentItems = current.get
         val newItems = currentItems match {
           case Nil => items
@@ -58,10 +58,10 @@ object TypedActorSpec {
         }
 
         if (current.compareAndSet(currentItems, newItems.tail)) newItems.head
-        else findNext
+        else findNext()
       }
 
-      findNext
+      findNext()
     }
 
     override def exists(f: T => Boolean): Boolean = items.exists(f)
@@ -122,7 +122,7 @@ object TypedActorSpec {
 
     import akka.actor.TypedActor.dispatcher
 
-    def pigdog = "Pigdog"
+    def pigdog() = "Pigdog"
 
     def futurePigdog(): Future[String] = Future.successful(pigdog())
 
@@ -133,7 +133,7 @@ object TypedActorSpec {
 
     def futurePigdog(delay: FiniteDuration, numbered: Int): Future[String] = {
       Thread.sleep(delay.toMillis)
-      Future.successful(pigdog + numbered)
+      Future.successful(pigdog() + numbered)
     }
 
     @silent
diff --git a/akka-actor-tests/src/test/scala/akka/dispatch/ExecutionContextSpec.scala b/akka-actor-tests/src/test/scala/akka/dispatch/ExecutionContextSpec.scala
index 1d7eb236fd..38cc323b91 100644
--- a/akka-actor-tests/src/test/scala/akka/dispatch/ExecutionContextSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/dispatch/ExecutionContextSpec.scala
@@ -208,9 +208,9 @@ class ExecutionContextSpec extends AkkaSpec with DefaultTimeout {
       awaitCond(counter.get == 2)
       perform(_ + 4)
       perform(_ * 2)
-      sec.size should ===(2)
+      sec.size() should ===(2)
       Thread.sleep(500)
-      sec.size should ===(2)
+      sec.size() should ===(2)
       counter.get should ===(2)
       sec.resume()
       awaitCond(counter.get == 12)
@@ -272,7 +272,7 @@ class ExecutionContextSpec extends AkkaSpec with DefaultTimeout {
       }
       perform(x => { sec.suspend(); x * 2 })
       perform(_ + 8)
-      sec.size should ===(13)
+      sec.size() should ===(13)
       sec.resume()
       awaitCond(counter.get == 2)
       sec.resume()
diff --git a/akka-actor-tests/src/test/scala/akka/dispatch/ForkJoinPoolStarvationSpec.scala b/akka-actor-tests/src/test/scala/akka/dispatch/ForkJoinPoolStarvationSpec.scala
index 36b11f0e5a..882e5c29e6 100644
--- a/akka-actor-tests/src/test/scala/akka/dispatch/ForkJoinPoolStarvationSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/dispatch/ForkJoinPoolStarvationSpec.scala
@@ -37,7 +37,7 @@ object ForkJoinPoolStarvationSpec {
 
     override def receive = {
       case "ping" =>
-        sender ! "All fine"
+        sender() ! "All fine"
     }
   }
 
diff --git a/akka-actor-tests/src/test/scala/akka/dispatch/MailboxConfigSpec.scala b/akka-actor-tests/src/test/scala/akka/dispatch/MailboxConfigSpec.scala
index b0ea9fd9bc..269dc9a526 100644
--- a/akka-actor-tests/src/test/scala/akka/dispatch/MailboxConfigSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/dispatch/MailboxConfigSpec.scala
@@ -60,7 +60,7 @@ abstract class MailboxSpec extends AkkaSpec with BeforeAndAfterAll with BeforeAn
       expectMsg(DeadLetter(exampleMessage.message, system.deadLetters, testActor))
       system.eventStream.unsubscribe(testActor, classOf[DeadLetter])
 
-      q.dequeue should ===(exampleMessage)
+      q.dequeue() should ===(exampleMessage)
       q.numberOfMessages should ===(config.capacity - 1)
       q.hasMessages should ===(true)
     }
@@ -98,7 +98,7 @@ abstract class MailboxSpec extends AkkaSpec with BeforeAndAfterAll with BeforeAn
   def ensureSingleConsumerEnqueueDequeue(config: MailboxType): Unit = {
     val q = factory(config)
     ensureMailboxSize(q, 0)
-    q.dequeue should ===(null)
+    q.dequeue() should ===(null)
     for (i <- 1 to 100) {
       q.enqueue(testActor, exampleMessage)
       ensureMailboxSize(q, i)
@@ -111,7 +111,7 @@ abstract class MailboxSpec extends AkkaSpec with BeforeAndAfterAll with BeforeAn
       ensureMailboxSize(q, i)
     }
 
-    q.dequeue should ===(null)
+    q.dequeue() should ===(null)
     ensureMailboxSize(q, 0)
   }
 
diff --git a/akka-actor-tests/src/test/scala/akka/event/EventBusSpec.scala b/akka-actor-tests/src/test/scala/akka/event/EventBusSpec.scala
index 3e6c6fca20..b3bbef09ed 100644
--- a/akka-actor-tests/src/test/scala/akka/event/EventBusSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/event/EventBusSpec.scala
@@ -329,7 +329,7 @@ object LookupEventBusSpec {
     override protected def classify(event: Int): String = event.toString
     override protected def compareSubscribers(a: Procedure[Int], b: Procedure[Int]): Int =
       akka.util.Helpers.compareIdentityHash(a, b)
-    override protected def mapSize = 32
+    override protected def mapSize() = 32
     override protected def publish(event: Int, subscriber: Procedure[Int]): Unit =
       subscriber(event)
   }
diff --git a/akka-actor-tests/src/test/scala/akka/io/TcpConnectionSpec.scala b/akka-actor-tests/src/test/scala/akka/io/TcpConnectionSpec.scala
index f6ea7a4a82..ea5a574663 100644
--- a/akka-actor-tests/src/test/scala/akka/io/TcpConnectionSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/io/TcpConnectionSpec.scala
@@ -956,7 +956,7 @@ class TcpConnectionSpec extends AkkaSpec("""
 
     override def run(body: => Unit): Unit = super.run {
       registerCallReceiver.expectMsg(Registration(clientSideChannel, 0))
-      registerCallReceiver.sender should ===(connectionActor)
+      registerCallReceiver.sender() should ===(connectionActor)
       body
     }
   }
diff --git a/akka-actor-tests/src/test/scala/akka/io/dns/internal/AsyncDnsResolverSpec.scala b/akka-actor-tests/src/test/scala/akka/io/dns/internal/AsyncDnsResolverSpec.scala
index 76b41a7995..cfe40a5db4 100644
--- a/akka-actor-tests/src/test/scala/akka/io/dns/internal/AsyncDnsResolverSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/io/dns/internal/AsyncDnsResolverSpec.scala
@@ -123,9 +123,13 @@ class AsyncDnsResolverSpec extends AkkaSpec("""
       r ! Resolve(name)
       dnsClient1.expectNoMessage(50.millis)
       val answer = senderProbe.expectMsgType[Resolved]
-      val Seq(AAAARecord("1:2:3:0:0:0:0:0", Ttl.effectivelyForever, _)) = answer.records.collect {
+      val Seq(aaaaRecord) = answer.records.collect {
         case r: AAAARecord => r
       }
+      aaaaRecord.name should be("1:2:3:0:0:0:0:0")
+      aaaaRecord.ttl should be(Ttl.effectivelyForever)
+      // The leading '/' indicates no reverse lookup was performed
+      aaaaRecord.ip.toString should be("/1:2:3:0:0:0:0:0")
     }
 
     "return additional records for SRV requests" in new Setup {
diff --git a/akka-actor-tests/src/test/scala/akka/pattern/BackoffOnRestartSupervisorSpec.scala b/akka-actor-tests/src/test/scala/akka/pattern/BackoffOnRestartSupervisorSpec.scala
index e6fa3b5a78..25f108be45 100644
--- a/akka-actor-tests/src/test/scala/akka/pattern/BackoffOnRestartSupervisorSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/pattern/BackoffOnRestartSupervisorSpec.scala
@@ -141,10 +141,10 @@ class BackoffOnRestartSupervisorSpec extends AkkaSpec("""
     class SlowlyFailingActor(latch: CountDownLatch) extends Actor {
       def receive: Receive = {
         case "THROW" =>
-          sender ! "THROWN"
+          sender() ! "THROWN"
           throw new NormalException
         case "PING" =>
-          sender ! "PONG"
+          sender() ! "PONG"
       }
 
       override def postStop(): Unit = {
diff --git a/akka-actor-tests/src/test/scala/akka/pattern/PipeToSpec.scala b/akka-actor-tests/src/test/scala/akka/pattern/PipeToSpec.scala
index 7d46323c1c..6615bc0998 100644
--- a/akka-actor-tests/src/test/scala/akka/pattern/PipeToSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/pattern/PipeToSpec.scala
@@ -44,7 +44,7 @@ class PipeToSpec extends AkkaSpec {
 
     "work in Java form with sender()" in {
       val p = TestProbe()
-      pipe(Future(42)) to (p.ref, testActor)
+      pipe(Future(42)).to(p.ref, testActor)
       p.expectMsg(42)
       p.lastSender should ===(testActor)
     }
@@ -86,7 +86,7 @@ class PipeToSpec extends AkkaSpec {
     "work in Java form with sender()" in {
       val p = TestProbe()
       val sel = system.actorSelection(p.ref.path)
-      pipe(Future(42)) to (sel, testActor)
+      pipe(Future(42)).to(sel, testActor)
       p.expectMsg(42)
       p.lastSender should ===(testActor)
     }
diff --git a/akka-actor-tests/src/test/scala/akka/routing/ConfiguredLocalRoutingSpec.scala b/akka-actor-tests/src/test/scala/akka/routing/ConfiguredLocalRoutingSpec.scala
index d3619c55ba..d34d80bee8 100644
--- a/akka-actor-tests/src/test/scala/akka/routing/ConfiguredLocalRoutingSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/routing/ConfiguredLocalRoutingSpec.scala
@@ -22,7 +22,6 @@ import akka.pattern.gracefulStop
 import akka.testkit.{ AkkaSpec, DefaultTimeout, ImplicitSender }
 import akka.testkit.TestActors.echoActorProps
 import akka.testkit.TestProbe
-import akka.testkit.TestProbe
 
 object ConfiguredLocalRoutingSpec {
   val config = """
diff --git a/akka-actor-tests/src/test/scala/akka/routing/MetricsBasedResizerSpec.scala b/akka-actor-tests/src/test/scala/akka/routing/MetricsBasedResizerSpec.scala
index c4d5336f55..a8c01e1299 100644
--- a/akka-actor-tests/src/test/scala/akka/routing/MetricsBasedResizerSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/routing/MetricsBasedResizerSpec.scala
@@ -71,7 +71,7 @@ object MetricsBasedResizerSpec {
 
 class MetricsBasedResizerSpec extends AkkaSpec(ResizerSpec.config) with DefaultTimeout with ImplicitSender {
 
-  override def atStartup: Unit = {
+  override def atStartup(): Unit = {
     // when shutting down some Resize messages might hang around
     system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*Resize")))
   }
diff --git a/akka-actor-tests/src/test/scala/akka/routing/ResizerSpec.scala b/akka-actor-tests/src/test/scala/akka/routing/ResizerSpec.scala
index 297f702458..5e53a3eb42 100644
--- a/akka-actor-tests/src/test/scala/akka/routing/ResizerSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/routing/ResizerSpec.scala
@@ -41,7 +41,7 @@ class ResizerSpec extends AkkaSpec(ResizerSpec.config) with DefaultTimeout with
 
   import akka.routing.ResizerSpec._
 
-  override def atStartup: Unit = {
+  override def atStartup(): Unit = {
     // when shutting down some Resize messages might hang around
     system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*Resize")))
   }
diff --git a/akka-actor-tests/src/test/scala/akka/routing/TailChoppingSpec.scala b/akka-actor-tests/src/test/scala/akka/routing/TailChoppingSpec.scala
index f53ed44e83..a62a3c6466 100644
--- a/akka-actor-tests/src/test/scala/akka/routing/TailChoppingSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/routing/TailChoppingSpec.scala
@@ -25,7 +25,7 @@ object TailChoppingSpec {
         case _ =>
           times += 1
           Thread.sleep(sleepTime.toMillis)
-          sender ! "ack"
+          sender() ! "ack"
       }
     }), "Actor:" + id)
 }
diff --git a/akka-actor-typed-tests/src/test/scala/akka/actor/typed/AskSpec.scala b/akka-actor-typed-tests/src/test/scala/akka/actor/typed/AskSpec.scala
index 3adc148374..c9998d149a 100644
--- a/akka-actor-typed-tests/src/test/scala/akka/actor/typed/AskSpec.scala
+++ b/akka-actor-typed-tests/src/test/scala/akka/actor/typed/AskSpec.scala
@@ -187,13 +187,13 @@ class AskSpec extends ScalaTestWithActorTestKit("""
 
   "askWithStatus pattern" must {
     "unwrap nested response a successful response" in {
-      val probe = createTestProbe[Request]
+      val probe = createTestProbe[Request]()
       val result: Future[String] = probe.ref.askWithStatus(Request(_))
       probe.expectMessageType[Request].replyTo ! StatusReply.success("goodie")
       result.futureValue should ===("goodie")
     }
     "fail future for a fail response with text" in {
-      val probe = createTestProbe[Request]
+      val probe = createTestProbe[Request]()
       val result: Future[String] = probe.ref.askWithStatus(Request(_))
       probe.expectMessageType[Request].replyTo ! StatusReply.error("boom")
       val exception = result.failed.futureValue
@@ -201,7 +201,7 @@ class AskSpec extends ScalaTestWithActorTestKit("""
       exception.getMessage should ===("boom")
     }
     "fail future for a fail response with custom exception" in {
-      val probe = createTestProbe[Request]
+      val probe = createTestProbe[Request]()
       val result: Future[String] = probe.ref.askWithStatus(Request(_))
       probe.expectMessageType[Request].replyTo ! StatusReply.error(TestException("boom"))
       val exception = result.failed.futureValue
diff --git a/akka-actor-typed-tests/src/test/scala/docs/akka/typed/FSMDocSpec.scala b/akka-actor-typed-tests/src/test/scala/docs/akka/typed/FSMDocSpec.scala
index 7d86a932b9..3b5b03d01f 100644
--- a/akka-actor-typed-tests/src/test/scala/docs/akka/typed/FSMDocSpec.scala
+++ b/akka-actor-typed-tests/src/test/scala/docs/akka/typed/FSMDocSpec.scala
@@ -80,7 +80,7 @@ class FSMDocSpec extends ScalaTestWithActorTestKit with AnyWordSpecLike with Log
   "FSMDocSpec" must {
     "work" in {
       val buncher = spawn(Buncher())
-      val probe = TestProbe[Buncher.Batch]
+      val probe = TestProbe[Buncher.Batch]()
       buncher ! Buncher.SetTarget(probe.ref)
       buncher ! Buncher.Queue(42)
       buncher ! Buncher.Queue(43)
diff --git a/akka-actor-typed-tests/src/test/scala/docs/akka/typed/coexistence/TypedWatchingClassicSpec.scala b/akka-actor-typed-tests/src/test/scala/docs/akka/typed/coexistence/TypedWatchingClassicSpec.scala
index 8109fea9d9..e1501f5153 100644
--- a/akka-actor-typed-tests/src/test/scala/docs/akka/typed/coexistence/TypedWatchingClassicSpec.scala
+++ b/akka-actor-typed-tests/src/test/scala/docs/akka/typed/coexistence/TypedWatchingClassicSpec.scala
@@ -8,7 +8,6 @@ import akka.actor.testkit.typed.scaladsl.LogCapturing
 import akka.actor.typed._
 import akka.actor.typed.scaladsl.Behaviors
 import akka.testkit.TestKit
-import docs.akka.typed.coexistence.TypedWatchingClassicSpec.Typed
 //#adapter-import
 // adds support for typed actors to a classic actor system and context
 import akka.actor.typed.scaladsl.adapter._
diff --git a/akka-actor-typed/src/main/scala/akka/actor/typed/internal/ActorContextImpl.scala b/akka-actor-typed/src/main/scala/akka/actor/typed/internal/ActorContextImpl.scala
index dd66ecde23..70dfcc2b4c 100644
--- a/akka-actor-typed/src/main/scala/akka/actor/typed/internal/ActorContextImpl.scala
+++ b/akka-actor-typed/src/main/scala/akka/actor/typed/internal/ActorContextImpl.scala
@@ -21,7 +21,7 @@ import akka.actor.typed.internal.adapter.ActorSystemAdapter
 import akka.annotation.InternalApi
 import akka.dispatch.ExecutionContexts
 import akka.pattern.StatusReply
-import akka.util.{ BoxedType, Timeout }
+import akka.util.BoxedType
 import akka.util.JavaDurationConverters._
 import akka.util.OptionVal
 import akka.util.Timeout
diff --git a/akka-actor-typed/src/main/scala/akka/actor/typed/internal/adapter/ActorSystemAdapter.scala b/akka-actor-typed/src/main/scala/akka/actor/typed/internal/adapter/ActorSystemAdapter.scala
index 367c3f88ce..2231b0526c 100644
--- a/akka-actor-typed/src/main/scala/akka/actor/typed/internal/adapter/ActorSystemAdapter.scala
+++ b/akka-actor-typed/src/main/scala/akka/actor/typed/internal/adapter/ActorSystemAdapter.scala
@@ -137,7 +137,7 @@ private[akka] object ActorSystemAdapter {
 
   object AdapterExtension extends classic.ExtensionId[AdapterExtension] with classic.ExtensionIdProvider {
     override def get(system: classic.ActorSystem): AdapterExtension = super.get(system)
-    override def lookup() = AdapterExtension
+    override def lookup = AdapterExtension
     override def createExtension(system: classic.ExtendedActorSystem): AdapterExtension =
       new AdapterExtension(system)
   }
@@ -154,7 +154,7 @@ private[akka] object ActorSystemAdapter {
   }
 
   object LoadTypedExtensions extends classic.ExtensionId[LoadTypedExtensions] with classic.ExtensionIdProvider {
-    override def lookup(): actor.ExtensionId[_ <: actor.Extension] = this
+    override def lookup: actor.ExtensionId[_ <: actor.Extension] = this
     override def createExtension(system: ExtendedActorSystem): LoadTypedExtensions =
       new LoadTypedExtensions(system)
   }
diff --git a/akka-actor/src/main/scala-2.13/akka/util/ByteString.scala b/akka-actor/src/main/scala-2.13/akka/util/ByteString.scala
index 0a81e0f726..f8d2f626d4 100644
--- a/akka-actor/src/main/scala-2.13/akka/util/ByteString.scala
+++ b/akka-actor/src/main/scala-2.13/akka/util/ByteString.scala
@@ -1347,7 +1347,7 @@ final class ByteStringBuilder extends Builder[Byte, ByteString] {
     _tempLength = 0
   }
 
-  def result: ByteString =
+  def result(): ByteString =
     if (_length == 0) ByteString.empty
     else {
       clearTemp()
diff --git a/akka-actor/src/main/scala/akka/actor/ActorSelection.scala b/akka-actor/src/main/scala/akka/actor/ActorSelection.scala
index 52b318531f..7b4497e1af 100644
--- a/akka-actor/src/main/scala/akka/actor/ActorSelection.scala
+++ b/akka-actor/src/main/scala/akka/actor/ActorSelection.scala
@@ -14,7 +14,6 @@ import scala.concurrent.Future
 import scala.concurrent.Promise
 import scala.concurrent.duration._
 import scala.language.implicitConversions
-import scala.language.implicitConversions
 import scala.util.Success
 
 import com.github.ghik.silencer.silent
diff --git a/akka-actor/src/main/scala/akka/actor/ActorSystem.scala b/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
index ea63ad7591..0082490ca4 100644
--- a/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
+++ b/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
@@ -1185,7 +1185,7 @@ private[akka] class ActorSystemImpl(
             dynamicAccess.createInstanceFor[AnyRef](fqcn, Nil).recoverWith { case _ => Failure(firstProblem) }
         } match {
           case Success(p: ExtensionIdProvider) =>
-            registerExtension(p.lookup())
+            registerExtension(p.lookup)
           case Success(p: ExtensionId[_]) =>
             registerExtension(p)
           case Success(_) =>
diff --git a/akka-actor/src/main/scala/akka/actor/Deployer.scala b/akka-actor/src/main/scala/akka/actor/Deployer.scala
index 0ea6c929f9..bf7228e52d 100644
--- a/akka-actor/src/main/scala/akka/actor/Deployer.scala
+++ b/akka-actor/src/main/scala/akka/actor/Deployer.scala
@@ -244,7 +244,8 @@ private[akka] class Deployer(val settings: ActorSystem.Settings, val dynamicAcce
   def lookup(path: Iterable[String]): Option[Deploy] = deployments.get().find(path)
 
   def deploy(d: Deploy): Unit = {
-    @tailrec def add(path: Array[String], d: Deploy, w: WildcardIndex[Deploy] = deployments.get): Unit = {
+    @tailrec def add(path: Array[String], d: Deploy): Unit = {
+      val w: WildcardIndex[Deploy] = deployments.get
       for (i <- path.indices) path(i) match {
         case "" => throw InvalidActorNameException(s"Actor name in deployment [${d.path}] must not be empty")
         case el => ActorPath.validatePathElement(el, fullPath = d.path)
diff --git a/akka-actor/src/main/scala/akka/actor/Extension.scala b/akka-actor/src/main/scala/akka/actor/Extension.scala
index 7d7d1857a0..5df5a63070 100644
--- a/akka-actor/src/main/scala/akka/actor/Extension.scala
+++ b/akka-actor/src/main/scala/akka/actor/Extension.scala
@@ -132,5 +132,5 @@ trait ExtensionIdProvider {
   /**
    * Returns the canonical ExtensionId for this Extension
    */
-  def lookup(): ExtensionId[_ <: Extension]
+  def lookup: ExtensionId[_ <: Extension]
 }
diff --git a/akka-actor/src/main/scala/akka/actor/Scheduler.scala b/akka-actor/src/main/scala/akka/actor/Scheduler.scala
index 4d170dd462..bf5289f958 100644
--- a/akka-actor/src/main/scala/akka/actor/Scheduler.scala
+++ b/akka-actor/src/main/scala/akka/actor/Scheduler.scala
@@ -11,7 +11,6 @@ import scala.concurrent.ExecutionContext
 import scala.concurrent.duration._
 import scala.util.control.NoStackTrace
 
-import com.github.ghik.silencer.silent
 import com.github.ghik.silencer.silent
 
 import akka.annotation.InternalApi
diff --git a/akka-actor/src/main/scala/akka/actor/TypedActor.scala b/akka-actor/src/main/scala/akka/actor/TypedActor.scala
index 02bee1c57b..20d9dbfd95 100644
--- a/akka-actor/src/main/scala/akka/actor/TypedActor.scala
+++ b/akka-actor/src/main/scala/akka/actor/TypedActor.scala
@@ -110,7 +110,7 @@ object TypedActor extends ExtensionId[TypedActorExtension] with ExtensionIdProvi
   override def get(system: ActorSystem): TypedActorExtension = super.get(system)
   override def get(system: ClassicActorSystemProvider): TypedActorExtension = super.get(system)
 
-  def lookup() = this
+  def lookup = this
   def createExtension(system: ExtendedActorSystem): TypedActorExtension = new TypedActorExtension(system)
 
   /**
diff --git a/akka-actor/src/main/scala/akka/dispatch/Dispatcher.scala b/akka-actor/src/main/scala/akka/dispatch/Dispatcher.scala
index 7aa810ada0..4a49e3eecd 100644
--- a/akka-actor/src/main/scala/akka/dispatch/Dispatcher.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/Dispatcher.scala
@@ -106,7 +106,7 @@ class Dispatcher(
   /**
    * INTERNAL API
    */
-  protected[akka] def shutdown: Unit = {
+  protected[akka] def shutdown(): Unit = {
     val newDelegate = executorServiceDelegate.copy() // Doesn't matter which one we copy
     val es = esUpdater.getAndSet(this, newDelegate)
     es.shutdown()
diff --git a/akka-actor/src/main/scala/akka/event/japi/EventBusJavaAPI.scala b/akka-actor/src/main/scala/akka/event/japi/EventBusJavaAPI.scala
index 0de71a0f5c..7abef391e4 100644
--- a/akka-actor/src/main/scala/akka/event/japi/EventBusJavaAPI.scala
+++ b/akka-actor/src/main/scala/akka/event/japi/EventBusJavaAPI.scala
@@ -50,7 +50,7 @@ abstract class LookupEventBus[E, S, C] extends EventBus[E, S, C] {
     type Subscriber = S
     type Classifier = C
 
-    override protected def mapSize: Int = LookupEventBus.this.mapSize()
+    override protected def mapSize(): Int = LookupEventBus.this.mapSize()
 
     override protected def compareSubscribers(a: S, b: S): Int =
       LookupEventBus.this.compareSubscribers(a, b)
diff --git a/akka-actor/src/main/scala/akka/io/Dns.scala b/akka-actor/src/main/scala/akka/io/Dns.scala
index 769b61ebea..cb7a8d733a 100644
--- a/akka-actor/src/main/scala/akka/io/Dns.scala
+++ b/akka-actor/src/main/scala/akka/io/Dns.scala
@@ -137,7 +137,7 @@ object Dns extends ExtensionId[DnsExt] with ExtensionIdProvider {
     Dns(system).cache.resolve(name, system, sender)
   }
 
-  override def lookup() = Dns
+  override def lookup = Dns
 
   override def createExtension(system: ExtendedActorSystem): DnsExt = new DnsExt(system)
 
diff --git a/akka-actor/src/main/scala/akka/io/TcpConnection.scala b/akka-actor/src/main/scala/akka/io/TcpConnection.scala
index d1b8ac5a7f..606272425a 100644
--- a/akka-actor/src/main/scala/akka/io/TcpConnection.scala
+++ b/akka-actor/src/main/scala/akka/io/TcpConnection.scala
@@ -415,9 +415,9 @@ private[io] abstract class TcpConnection(val tcp: TcpExt, val channel: SocketCha
     throw new IllegalStateException("Restarting not supported for connection actors.")
 
   def PendingWrite(commander: ActorRef, write: WriteCommand): PendingWrite = {
-    @tailrec def create(head: WriteCommand, tail: WriteCommand = Write.empty): PendingWrite =
+    @tailrec def create(head: WriteCommand, tail: WriteCommand): PendingWrite =
       head match {
-        case Write.empty                       => if (tail eq Write.empty) EmptyPendingWrite else create(tail)
+        case Write.empty                       => if (tail eq Write.empty) EmptyPendingWrite else create(tail, Write.empty)
         case Write(data, ack) if data.nonEmpty => PendingBufferWrite(commander, data, ack, tail)
         case WriteFile(path, offset, count, ack) =>
           PendingWriteFile(commander, Paths.get(path), offset, count, ack, tail)
@@ -426,9 +426,9 @@ private[io] abstract class TcpConnection(val tcp: TcpExt, val channel: SocketCha
         case CompoundWrite(h, t) => create(h, t)
         case x @ Write(_, ack) => // empty write with either an ACK or a non-standard NoACK
           if (x.wantsAck) commander ! ack
-          create(tail)
+          create(tail, Write.empty)
       }
-    create(write)
+    create(write, Write.empty)
   }
 
   def PendingBufferWrite(commander: ActorRef, data: ByteString, ack: Event, tail: WriteCommand): PendingBufferWrite = {
diff --git a/akka-actor/src/main/scala/akka/io/dns/internal/TcpDnsClient.scala b/akka-actor/src/main/scala/akka/io/dns/internal/TcpDnsClient.scala
index 1a3f99773b..3392904f9a 100644
--- a/akka-actor/src/main/scala/akka/io/dns/internal/TcpDnsClient.scala
+++ b/akka-actor/src/main/scala/akka/io/dns/internal/TcpDnsClient.scala
@@ -63,7 +63,7 @@ import akka.util.ByteString
           context.become(ready(connection, data))
         else {
           answerRecipient ! parseResponse(data.drop(prefixSize))
-          context.become(ready(connection))
+          context.become(ready(connection, ByteString.empty))
           if (data.length > prefixSize + expectedPayloadLength) {
             self ! Tcp.Received(data.drop(prefixSize + expectedPayloadLength))
           }
diff --git a/akka-actor/src/main/scala/akka/util/ManifestInfo.scala b/akka-actor/src/main/scala/akka/util/ManifestInfo.scala
index e3c86c7f5c..913050be75 100644
--- a/akka-actor/src/main/scala/akka/util/ManifestInfo.scala
+++ b/akka-actor/src/main/scala/akka/util/ManifestInfo.scala
@@ -45,7 +45,7 @@ object ManifestInfo extends ExtensionId[ManifestInfo] with ExtensionIdProvider {
   override def get(system: ActorSystem): ManifestInfo = super.get(system)
   override def get(system: ClassicActorSystemProvider): ManifestInfo = super.get(system)
 
-  override def lookup(): ManifestInfo.type = ManifestInfo
+  override def lookup: ManifestInfo.type = ManifestInfo
 
   override def createExtension(system: ExtendedActorSystem): ManifestInfo = new ManifestInfo(system)
 
diff --git a/akka-bench-jmh/src/main/scala/akka/actor/TellOnlyBenchmark.scala b/akka-bench-jmh/src/main/scala/akka/actor/TellOnlyBenchmark.scala
index 7ba3618a8f..32112ca525 100644
--- a/akka-bench-jmh/src/main/scala/akka/actor/TellOnlyBenchmark.scala
+++ b/akka-bench-jmh/src/main/scala/akka/actor/TellOnlyBenchmark.scala
@@ -102,7 +102,7 @@ object TellOnlyBenchmark {
     def receive = {
       case `stop` =>
         context.stop(self)
-      case m => sender ! m
+      case m => sender() ! m
     }
   }
 
diff --git a/akka-bench-jmh/src/main/scala/akka/persistence/PersistentActorWithAtLeastOnceDeliveryBenchmark.scala b/akka-bench-jmh/src/main/scala/akka/persistence/PersistentActorWithAtLeastOnceDeliveryBenchmark.scala
index 03ab940536..0ed9b57b76 100644
--- a/akka-bench-jmh/src/main/scala/akka/persistence/PersistentActorWithAtLeastOnceDeliveryBenchmark.scala
+++ b/akka-bench-jmh/src/main/scala/akka/persistence/PersistentActorWithAtLeastOnceDeliveryBenchmark.scala
@@ -8,7 +8,6 @@ import java.io.File
 
 import scala.concurrent.Await
 import scala.concurrent.duration._
-import scala.concurrent.duration._
 
 import org.apache.commons.io.FileUtils
 import org.openjdk.jmh.annotations._
diff --git a/akka-bench-jmh/src/main/scala/akka/stream/InterpreterBenchmark.scala b/akka-bench-jmh/src/main/scala/akka/stream/InterpreterBenchmark.scala
index 00f4b08d7f..fc8759ed52 100644
--- a/akka-bench-jmh/src/main/scala/akka/stream/InterpreterBenchmark.scala
+++ b/akka-bench-jmh/src/main/scala/akka/stream/InterpreterBenchmark.scala
@@ -9,7 +9,7 @@ import java.util.concurrent.TimeUnit
 import org.openjdk.jmh.annotations._
 
 import akka.event._
-import akka.stream.impl.fusing.{ GraphInterpreterSpecKit, GraphStages }
+import akka.stream.impl.fusing.GraphInterpreterSpecKit
 import akka.stream.impl.fusing.GraphInterpreter.{ DownstreamBoundaryStageLogic, UpstreamBoundaryStageLogic }
 import akka.stream.impl.fusing.GraphStages
 import akka.stream.stage._
diff --git a/akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsCollector.scala b/akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsCollector.scala
index ed7a705edb..2b700850d9 100644
--- a/akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsCollector.scala
+++ b/akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsCollector.scala
@@ -200,7 +200,7 @@ private[metrics] class ClusterMetricsCollector extends Actor with ActorLogging {
 
   }
 
-  override def postStop: Unit = {
+  override def postStop(): Unit = {
     cluster.unsubscribe(self)
     gossipTask.cancel()
     sampleTask.cancel()
diff --git a/akka-cluster-sharding-typed/src/multi-jvm/scala/akka/cluster/sharding/ClusterShardingRememberEntitiesPerfSpec.scala b/akka-cluster-sharding-typed/src/multi-jvm/scala/akka/cluster/sharding/ClusterShardingRememberEntitiesPerfSpec.scala
index 066e76f9fe..6aeea11f44 100644
--- a/akka-cluster-sharding-typed/src/multi-jvm/scala/akka/cluster/sharding/ClusterShardingRememberEntitiesPerfSpec.scala
+++ b/akka-cluster-sharding-typed/src/multi-jvm/scala/akka/cluster/sharding/ClusterShardingRememberEntitiesPerfSpec.scala
@@ -96,8 +96,6 @@ abstract class ClusterShardingRememberEntitiesPerfSpec
   import ClusterShardingRememberEntitiesPerfSpec._
   import ClusterShardingRememberEntitiesPerfSpecConfig._
 
-  import ClusterShardingRememberEntitiesPerfSpec._
-
   def startSharding(): Unit = {
     (1 to NrRegions).foreach { n =>
       startSharding(
diff --git a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardRegion.scala b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardRegion.scala
index 01c86bfaba..6f9bd86727 100644
--- a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardRegion.scala
+++ b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardRegion.scala
@@ -812,7 +812,7 @@ private[akka] class ShardRegion(
       }
 
     case msg: GetClusterShardingStats =>
-      coordinator.fold(sender ! ClusterShardingStats(Map.empty))(_.forward(msg))
+      coordinator.fold(sender() ! ClusterShardingStats(Map.empty))(_.forward(msg))
 
     case GetShardRegionState =>
       replyToRegionStateQuery(sender())
diff --git a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardingFlightRecorder.scala b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardingFlightRecorder.scala
index 3c0c52cab3..787ff8d967 100644
--- a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardingFlightRecorder.scala
+++ b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/ShardingFlightRecorder.scala
@@ -13,7 +13,7 @@ import akka.util.FlightRecorderLoader
 @InternalApi
 object ShardingFlightRecorder extends ExtensionId[ShardingFlightRecorder] with ExtensionIdProvider {
 
-  override def lookup(): ExtensionId[_ <: Extension] = this
+  override def lookup: ExtensionId[_ <: Extension] = this
 
   override def createExtension(system: ExtendedActorSystem): ShardingFlightRecorder =
     FlightRecorderLoader.load[ShardingFlightRecorder](
diff --git a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/external/ExternalShardAllocation.scala b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/external/ExternalShardAllocation.scala
index 9fb95e3096..8a6256375d 100644
--- a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/external/ExternalShardAllocation.scala
+++ b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/external/ExternalShardAllocation.scala
@@ -48,7 +48,7 @@ object ExternalShardAllocation extends ExtensionId[ExternalShardAllocation] with
   override def createExtension(system: ExtendedActorSystem): ExternalShardAllocation =
     new ExternalShardAllocation(system)
 
-  override def lookup(): ExternalShardAllocation.type = ExternalShardAllocation
+  override def lookup: ExternalShardAllocation.type = ExternalShardAllocation
 
   override def get(system: ClassicActorSystemProvider): ExternalShardAllocation = super.get(system)
 }
diff --git a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala
index aa8b361daf..5785386831 100644
--- a/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala
+++ b/akka-cluster-sharding/src/main/scala/akka/cluster/sharding/protobuf/ClusterShardingMessageSerializer.scala
@@ -10,8 +10,6 @@ import java.util.zip.GZIPInputStream
 import java.util.zip.GZIPOutputStream
 
 import scala.annotation.tailrec
-import scala.concurrent.duration._
-import akka.util.ccompat.JavaConverters._
 import scala.collection.immutable
 import scala.concurrent.duration._
 
@@ -34,7 +32,6 @@ import akka.serialization.BaseSerializer
 import akka.serialization.Serialization
 import akka.serialization.SerializerWithStringManifest
 import akka.util.ccompat._
-
 import akka.util.ccompat.JavaConverters._
 
 /**
diff --git a/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/PersistentStartEntitySpec.scala b/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/PersistentStartEntitySpec.scala
index 8dfaaf903d..6a1f1db010 100644
--- a/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/PersistentStartEntitySpec.scala
+++ b/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/PersistentStartEntitySpec.scala
@@ -72,7 +72,7 @@ class PersistentStartEntitySpec
     "remember entities started with StartEntity" in {
       val sharding = ClusterSharding(system).start(
         s"startEntity",
-        Props[EntityActor],
+        Props[EntityActor](),
         ClusterShardingSettings(system)
           .withRememberEntities(true)
           .withStateStoreMode(ClusterShardingSettings.StateStoreModePersistence),
diff --git a/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/RememberEntitiesFailureSpec.scala b/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/RememberEntitiesFailureSpec.scala
index bb47325f98..f34aefb0f1 100644
--- a/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/RememberEntitiesFailureSpec.scala
+++ b/akka-cluster-sharding/src/test/scala/akka/cluster/sharding/RememberEntitiesFailureSpec.scala
@@ -105,7 +105,7 @@ object RememberEntitiesFailureSpec {
     override def receive: Receive = {
       case RememberEntitiesShardStore.GetEntities =>
         failShardGetEntities.get(shardId) match {
-          case None             => sender ! RememberEntitiesShardStore.RememberedEntities(Set.empty)
+          case None             => sender() ! RememberEntitiesShardStore.RememberedEntities(Set.empty)
           case Some(NoResponse) => log.debug("Sending no response for GetEntities")
           case Some(CrashStore) => throw TestException("store crash on GetEntities")
           case Some(StopStore)  => context.stop(self)
@@ -115,7 +115,7 @@ object RememberEntitiesFailureSpec {
         }
       case RememberEntitiesShardStore.Update(started, stopped) =>
         failUpdate match {
-          case None             => sender ! RememberEntitiesShardStore.UpdateDone(started, stopped)
+          case None             => sender() ! RememberEntitiesShardStore.UpdateDone(started, stopped)
           case Some(NoResponse) => log.debug("Sending no response for AddEntity")
           case Some(CrashStore) => throw TestException("store crash on AddEntity")
           case Some(StopStore)  => context.stop(self)
@@ -209,7 +209,7 @@ class RememberEntitiesFailureSpec
           val probe = TestProbe()
           val sharding = ClusterSharding(system).start(
             s"initial-$wayToFail",
-            Props[EntityActor],
+            Props[EntityActor](),
             ClusterShardingSettings(system).withRememberEntities(true),
             extractEntityId,
             extractShardId)
@@ -238,7 +238,7 @@ class RememberEntitiesFailureSpec
 
         val sharding = ClusterSharding(system).start(
           s"shardStoreStart-$wayToFail",
-          Props[EntityActor],
+          Props[EntityActor](),
           ClusterShardingSettings(system).withRememberEntities(true),
           extractEntityId,
           extractShardId)
@@ -280,7 +280,7 @@ class RememberEntitiesFailureSpec
 
         val sharding = ClusterSharding(system).start(
           s"shardStoreStopAbrupt-$wayToFail",
-          Props[EntityActor],
+          Props[EntityActor](),
           ClusterShardingSettings(system).withRememberEntities(true),
           extractEntityId,
           extractShardId)
@@ -316,7 +316,7 @@ class RememberEntitiesFailureSpec
 
         val sharding = ClusterSharding(system).start(
           s"shardStoreStopGraceful-$wayToFail",
-          Props[EntityActor],
+          Props[EntityActor](),
           ClusterShardingSettings(system).withRememberEntities(true),
           extractEntityId,
           extractShardId,
@@ -357,7 +357,7 @@ class RememberEntitiesFailureSpec
 
         val sharding = ClusterSharding(system).start(
           s"coordinatorStoreStopGraceful-$wayToFail",
-          Props[EntityActor],
+          Props[EntityActor](),
           ClusterShardingSettings(system).withRememberEntities(true),
           extractEntityId,
           extractShardId,
diff --git a/akka-cluster-tools/src/main/scala/akka/cluster/client/ClusterClient.scala b/akka-cluster-tools/src/main/scala/akka/cluster/client/ClusterClient.scala
index 8e0e62b34f..4a6bdbc84f 100644
--- a/akka-cluster-tools/src/main/scala/akka/cluster/client/ClusterClient.scala
+++ b/akka-cluster-tools/src/main/scala/akka/cluster/client/ClusterClient.scala
@@ -561,7 +561,7 @@ object ClusterClientReceptionist extends ExtensionId[ClusterClientReceptionist]
   override def get(system: ActorSystem): ClusterClientReceptionist = super.get(system)
   override def get(system: ClassicActorSystemProvider): ClusterClientReceptionist = super.get(system)
 
-  override def lookup() = ClusterClientReceptionist
+  override def lookup = ClusterClientReceptionist
 
   override def createExtension(system: ExtendedActorSystem): ClusterClientReceptionist =
     new ClusterClientReceptionist(system)
diff --git a/akka-cluster-tools/src/main/scala/akka/cluster/pubsub/DistributedPubSubMediator.scala b/akka-cluster-tools/src/main/scala/akka/cluster/pubsub/DistributedPubSubMediator.scala
index 79a5692b3a..f8cce95bbe 100644
--- a/akka-cluster-tools/src/main/scala/akka/cluster/pubsub/DistributedPubSubMediator.scala
+++ b/akka-cluster-tools/src/main/scala/akka/cluster/pubsub/DistributedPubSubMediator.scala
@@ -674,7 +674,7 @@ class DistributedPubSubMediator(settings: DistributedPubSubSettings)
       forwardMessages(key, sender())
 
     case GetTopics =>
-      sender ! CurrentTopics(getCurrentTopics())
+      sender() ! CurrentTopics(getCurrentTopics())
 
     case Subscribed(ack, ref) =>
       ref ! ack
diff --git a/akka-cluster/src/multi-jvm/scala/akka/cluster/AttemptSysMsgRedeliverySpec.scala b/akka-cluster/src/multi-jvm/scala/akka/cluster/AttemptSysMsgRedeliverySpec.scala
index 437d8f87b8..a7707b8dc1 100644
--- a/akka-cluster/src/multi-jvm/scala/akka/cluster/AttemptSysMsgRedeliverySpec.scala
+++ b/akka-cluster/src/multi-jvm/scala/akka/cluster/AttemptSysMsgRedeliverySpec.scala
@@ -28,7 +28,7 @@ object AttemptSysMsgRedeliveryMultiJvmSpec extends MultiNodeConfig {
 
   class Echo extends Actor {
     def receive = {
-      case m => sender ! m
+      case m => sender() ! m
     }
   }
 }
diff --git a/akka-cluster/src/multi-jvm/scala/akka/cluster/SplitBrainSpec.scala b/akka-cluster/src/multi-jvm/scala/akka/cluster/SplitBrainSpec.scala
index cb80356555..59be478902 100644
--- a/akka-cluster/src/multi-jvm/scala/akka/cluster/SplitBrainSpec.scala
+++ b/akka-cluster/src/multi-jvm/scala/akka/cluster/SplitBrainSpec.scala
@@ -4,7 +4,6 @@
 
 package akka.cluster
 
-import scala.concurrent.duration._
 import scala.concurrent.duration._
 
 import com.typesafe.config.ConfigFactory
diff --git a/akka-cluster/src/multi-jvm/scala/akka/cluster/SurviveNetworkInstabilitySpec.scala b/akka-cluster/src/multi-jvm/scala/akka/cluster/SurviveNetworkInstabilitySpec.scala
index ffd1b60ea5..3cb6faaa8c 100644
--- a/akka-cluster/src/multi-jvm/scala/akka/cluster/SurviveNetworkInstabilitySpec.scala
+++ b/akka-cluster/src/multi-jvm/scala/akka/cluster/SurviveNetworkInstabilitySpec.scala
@@ -48,7 +48,7 @@ object SurviveNetworkInstabilityMultiJvmSpec extends MultiNodeConfig {
 
   class Echo extends Actor {
     def receive = {
-      case m => sender ! m
+      case m => sender() ! m
     }
   }
 
diff --git a/akka-cluster/src/test/scala/akka/cluster/VectorClockPerfSpec.scala b/akka-cluster/src/test/scala/akka/cluster/VectorClockPerfSpec.scala
index 854022a99d..49fa20a932 100644
--- a/akka-cluster/src/test/scala/akka/cluster/VectorClockPerfSpec.scala
+++ b/akka-cluster/src/test/scala/akka/cluster/VectorClockPerfSpec.scala
@@ -59,7 +59,7 @@ class VectorClockPerfSpec extends AnyWordSpec with Matchers {
     vc1.compareTo(vc2) should ===(order)
   }
 
-  def !==(vc1: VectorClock, vc2: VectorClock): Unit = {
+  def notEqual(vc1: VectorClock, vc2: VectorClock): Unit = {
     vc1 == vc2 should ===(false)
   }
 
@@ -98,15 +98,15 @@ class VectorClockPerfSpec extends AnyWordSpec with Matchers {
     }
 
     s"compare !== Before (middle) $iterations times" in {
-      checkThunkFor(vcBefore, vcBaseMiddle, !==, iterations)
+      checkThunkFor(vcBefore, vcBaseMiddle, notEqual, iterations)
     }
 
     s"compare !== After (middle) $iterations times" in {
-      checkThunkFor(vcAfterMiddle, vcBaseMiddle, !==, iterations)
+      checkThunkFor(vcAfterMiddle, vcBaseMiddle, notEqual, iterations)
     }
 
     s"compare !== Concurrent (middle) $iterations times" in {
-      checkThunkFor(vcAfterMiddle, vcConcurrentMiddle, !==, iterations)
+      checkThunkFor(vcAfterMiddle, vcConcurrentMiddle, notEqual, iterations)
     }
 
   }
diff --git a/akka-distributed-data/src/main/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializer.scala b/akka-distributed-data/src/main/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializer.scala
index 19da5d8a29..c02b8f6200 100644
--- a/akka-distributed-data/src/main/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializer.scala
+++ b/akka-distributed-data/src/main/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializer.scala
@@ -4,7 +4,7 @@
 
 package akka.cluster.ddata.protobuf
 
-import java.{ util, lang => jl }
+import java.{ lang => jl }
 import java.io.NotSerializableException
 import java.util
 import java.util.ArrayList
@@ -23,7 +23,7 @@ import akka.cluster.ddata.Replicator.Internal._
 import akka.cluster.ddata.protobuf.msg.{ ReplicatedDataMessages => rd }
 import akka.cluster.ddata.protobuf.msg.{ ReplicatorMessages => dm }
 import akka.cluster.ddata.protobuf.msg.ReplicatorMessages.OtherMessage
-import akka.protobufv3.internal.{ ByteString, GeneratedMessageV3 }
+import akka.protobufv3.internal.ByteString
 import akka.protobufv3.internal.GeneratedMessageV3
 import akka.serialization.BaseSerializer
 import akka.serialization.Serialization
diff --git a/akka-distributed-data/src/test/scala/akka/cluster/ddata/VersionVectorSpec.scala b/akka-distributed-data/src/test/scala/akka/cluster/ddata/VersionVectorSpec.scala
index 145610ef5d..dc3f357565 100644
--- a/akka-distributed-data/src/test/scala/akka/cluster/ddata/VersionVectorSpec.scala
+++ b/akka-distributed-data/src/test/scala/akka/cluster/ddata/VersionVectorSpec.scala
@@ -24,7 +24,7 @@ class VersionVectorSpec
   val node3 = UniqueAddress(node1.address.copy(port = Some(2553)), 3L)
   val node4 = UniqueAddress(node1.address.copy(port = Some(2554)), 4L)
 
-  override def afterAll: Unit = {
+  override def afterAll(): Unit = {
     shutdown()
   }
 
diff --git a/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializerSpec.scala b/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializerSpec.scala
index 2ebf8ec347..a7ef77b9a2 100644
--- a/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializerSpec.scala
+++ b/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatedDataSerializerSpec.scala
@@ -53,7 +53,7 @@ class ReplicatedDataSerializerSpec
   val ref2 = system.actorOf(Props.empty, "ref2")
   val ref3 = system.actorOf(Props.empty, "ref3")
 
-  override def afterAll: Unit = {
+  override def afterAll(): Unit = {
     shutdown()
   }
 
diff --git a/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatorMessageSerializerSpec.scala b/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatorMessageSerializerSpec.scala
index a8f0ea018f..25e6150bbc 100644
--- a/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatorMessageSerializerSpec.scala
+++ b/akka-distributed-data/src/test/scala/akka/cluster/ddata/protobuf/ReplicatorMessageSerializerSpec.scala
@@ -54,7 +54,7 @@ class ReplicatorMessageSerializerSpec
 
   val keyA = GSetKey[String]("A")
 
-  override def afterAll: Unit = {
+  override def afterAll(): Unit = {
     shutdown()
   }
 
diff --git a/akka-multi-node-testkit/src/main/scala/akka/remote/testkit/MultiNodeSpec.scala b/akka-multi-node-testkit/src/main/scala/akka/remote/testkit/MultiNodeSpec.scala
index edffba336b..b6b915d6e4 100644
--- a/akka-multi-node-testkit/src/main/scala/akka/remote/testkit/MultiNodeSpec.scala
+++ b/akka-multi-node-testkit/src/main/scala/akka/remote/testkit/MultiNodeSpec.scala
@@ -298,11 +298,11 @@ abstract class MultiNodeSpec(
     def await: T = Await.result(w, remainingOr(testConductor.Settings.QueryTimeout.duration))
   }
 
-  final override def multiNodeSpecBeforeAll: Unit = {
+  final override def multiNodeSpecBeforeAll(): Unit = {
     atStartup()
   }
 
-  final override def multiNodeSpecAfterAll: Unit = {
+  final override def multiNodeSpecAfterAll(): Unit = {
     // wait for all nodes to remove themselves before we shut the conductor down
     if (selfIndex == 0) {
       testConductor.removeNode(myself)
diff --git a/akka-osgi/src/test/scala/docs/osgi/Activator.scala b/akka-osgi/src/test/scala/docs/osgi/Activator.scala
index 7ce0957b6e..b39deb750c 100644
--- a/akka-osgi/src/test/scala/docs/osgi/Activator.scala
+++ b/akka-osgi/src/test/scala/docs/osgi/Activator.scala
@@ -21,7 +21,7 @@ class Activator extends ActorSystemActivator {
     // optionally register the ActorSystem in the OSGi Service Registry
     registerService(context, system)
 
-    val someActor = system.actorOf(Props[SomeActor], name = "someName")
+    val someActor = system.actorOf(Props[SomeActor](), name = "someName")
     someActor ! SomeMessage
   }
 
diff --git a/akka-persistence-query/src/main/scala/akka/persistence/query/PersistenceQuery.scala b/akka-persistence-query/src/main/scala/akka/persistence/query/PersistenceQuery.scala
index 11c45f3fb1..244f75d0d6 100644
--- a/akka-persistence-query/src/main/scala/akka/persistence/query/PersistenceQuery.scala
+++ b/akka-persistence-query/src/main/scala/akka/persistence/query/PersistenceQuery.scala
@@ -24,7 +24,7 @@ object PersistenceQuery extends ExtensionId[PersistenceQuery] with ExtensionIdPr
 
   def createExtension(system: ExtendedActorSystem): PersistenceQuery = new PersistenceQuery(system)
 
-  def lookup(): PersistenceQuery.type = PersistenceQuery
+  def lookup: PersistenceQuery.type = PersistenceQuery
 
   @InternalApi
   private[akka] val pluginProvider: PluginProvider[ReadJournalProvider, ReadJournal, javadsl.ReadJournal] =
diff --git a/akka-persistence-tck/src/main/scala/akka/persistence/scalatest/MayVerb.scala b/akka-persistence-tck/src/main/scala/akka/persistence/scalatest/MayVerb.scala
index 427e0d8a5d..21f9ca0c64 100644
--- a/akka-persistence-tck/src/main/scala/akka/persistence/scalatest/MayVerb.scala
+++ b/akka-persistence-tck/src/main/scala/akka/persistence/scalatest/MayVerb.scala
@@ -41,7 +41,7 @@ trait MayVerb {
      * @see <a href="https://www.rfc-editor.org/rfc/rfc2119.txt">RFC 2119</a>
      */
     def may(right: => Unit)(implicit fun: StringVerbBlockRegistration, pos: Position): Unit = {
-      fun(leftSideString, "may", pos, right _)
+      fun(leftSideString, "may", pos, () => right)
     }
   }
 
diff --git a/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/InMemStorageExtension.scala b/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/InMemStorageExtension.scala
index fb55631be1..83652f3b56 100644
--- a/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/InMemStorageExtension.scala
+++ b/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/InMemStorageExtension.scala
@@ -24,6 +24,6 @@ private[testkit] object InMemStorageExtension extends ExtensionId[EventStorage]
       new SimpleEventStorageImpl
     }
 
-  override def lookup() = InMemStorageExtension
+  override def lookup = InMemStorageExtension
 
 }
diff --git a/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/SnapshotStorageEmulatorExtension.scala b/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/SnapshotStorageEmulatorExtension.scala
index 276a72897a..56e5b86153 100644
--- a/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/SnapshotStorageEmulatorExtension.scala
+++ b/akka-persistence-testkit/src/main/scala/akka/persistence/testkit/internal/SnapshotStorageEmulatorExtension.scala
@@ -24,6 +24,6 @@ private[testkit] object SnapshotStorageEmulatorExtension extends ExtensionId[Sna
       new SimpleSnapshotStorageImpl
     }
 
-  override def lookup(): ExtensionId[_ <: Extension] =
+  override def lookup: ExtensionId[_ <: Extension] =
     SnapshotStorageEmulatorExtension
 }
diff --git a/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorFailureSpec.scala b/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorFailureSpec.scala
index 3cf4ee20ac..a6ba8b2f66 100644
--- a/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorFailureSpec.scala
+++ b/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorFailureSpec.scala
@@ -28,7 +28,6 @@ import akka.persistence.journal.inmem.InmemJournal
 import akka.persistence.typed.EventRejectedException
 import akka.persistence.typed.PersistenceId
 import akka.persistence.typed.RecoveryCompleted
-import akka.persistence.typed.RecoveryCompleted
 import akka.persistence.typed.RecoveryFailed
 import akka.persistence.typed.internal.JournalFailureException
 
diff --git a/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorSpec.scala b/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorSpec.scala
index 25f4f9042c..e55fc651b1 100644
--- a/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorSpec.scala
+++ b/akka-persistence-typed/src/test/scala/akka/persistence/typed/scaladsl/EventSourcedBehaviorSpec.scala
@@ -348,7 +348,7 @@ class EventSourcedBehaviorSpec
 
     "adhere default and disabled Recovery strategies" in {
       val pid = nextPid()
-      val probe = TestProbe[State]
+      val probe = TestProbe[State]()
 
       def counterWithRecoveryStrategy(recoveryStrategy: Recovery) =
         Behaviors.setup[Command](counter(_, pid).withRecovery(recoveryStrategy))
@@ -374,9 +374,9 @@ class EventSourcedBehaviorSpec
 
     "adhere Recovery strategy with SnapshotSelectionCriteria" in {
       val pid = nextPid()
-      val eventProbe = TestProbe[(State, Event)]
-      val commandProbe = TestProbe[State]
-      val snapshotProbe = TestProbe[Try[SnapshotMetadata]]
+      val eventProbe = TestProbe[(State, Event)]()
+      val commandProbe = TestProbe[State]()
+      val snapshotProbe = TestProbe[Try[SnapshotMetadata]]()
 
       def counterWithSnapshotSelectionCriteria(recoveryStrategy: Recovery) =
         Behaviors.setup[Command](
diff --git a/akka-persistence/src/main/scala/akka/persistence/AtLeastOnceDelivery.scala b/akka-persistence/src/main/scala/akka/persistence/AtLeastOnceDelivery.scala
index 166633e1ae..a7ae70c923 100644
--- a/akka-persistence/src/main/scala/akka/persistence/AtLeastOnceDelivery.scala
+++ b/akka-persistence/src/main/scala/akka/persistence/AtLeastOnceDelivery.scala
@@ -11,7 +11,6 @@ import akka.actor.{ ActorPath, ActorSelection, NotInfluenceReceiveTimeout }
 import akka.actor.Cancellable
 import akka.actor.DeadLetterSuppression
 import akka.annotation.InternalApi
-import akka.persistence.AtLeastOnceDelivery.Internal.Delivery
 import akka.persistence.serialization.Message
 import akka.util.ccompat._
 
diff --git a/akka-persistence/src/main/scala/akka/persistence/Persistence.scala b/akka-persistence/src/main/scala/akka/persistence/Persistence.scala
index 317c5f32be..efd6027d7b 100644
--- a/akka-persistence/src/main/scala/akka/persistence/Persistence.scala
+++ b/akka-persistence/src/main/scala/akka/persistence/Persistence.scala
@@ -149,7 +149,7 @@ object Persistence extends ExtensionId[Persistence] with ExtensionIdProvider {
 
   def createExtension(system: ExtendedActorSystem): Persistence = new Persistence(system)
 
-  def lookup() = Persistence
+  def lookup = Persistence
 
   /** INTERNAL API. */
   private[persistence] case class PluginHolder(actorFactory: () => ActorRef, adapters: EventAdapters, config: Config)
diff --git a/akka-persistence/src/main/scala/akka/persistence/journal/PersistencePluginProxy.scala b/akka-persistence/src/main/scala/akka/persistence/journal/PersistencePluginProxy.scala
index e33296cec1..ace18692f1 100644
--- a/akka-persistence/src/main/scala/akka/persistence/journal/PersistencePluginProxy.scala
+++ b/akka-persistence/src/main/scala/akka/persistence/journal/PersistencePluginProxy.scala
@@ -67,7 +67,7 @@ object PersistencePluginProxyExtension
     with ExtensionIdProvider {
   override def createExtension(system: ExtendedActorSystem): PersistencePluginProxyExtensionImpl =
     new PersistencePluginProxyExtensionImpl(system)
-  override def lookup(): ExtensionId[_ <: Extension] = PersistencePluginProxyExtension
+  override def lookup: ExtensionId[_ <: Extension] = PersistencePluginProxyExtension
   override def get(system: ActorSystem): PersistencePluginProxyExtensionImpl = super.get(system)
   override def get(system: ClassicActorSystemProvider): PersistencePluginProxyExtensionImpl = super.get(system)
 }
diff --git a/akka-persistence/src/main/scala/akka/persistence/snapshot/SnapshotStore.scala b/akka-persistence/src/main/scala/akka/persistence/snapshot/SnapshotStore.scala
index 31094b8100..e24e7ec21a 100644
--- a/akka-persistence/src/main/scala/akka/persistence/snapshot/SnapshotStore.scala
+++ b/akka-persistence/src/main/scala/akka/persistence/snapshot/SnapshotStore.scala
@@ -61,11 +61,12 @@ trait SnapshotStore extends Actor with ActorLogging {
           }
           .recover {
             case e => SaveSnapshotFailure(metadata, e)
-          } to (self, senderPersistentActor())
+          }
+          .to(self, senderPersistentActor())
 
       case evt: SaveSnapshotSuccess =>
         try tryReceivePluginInternal(evt)
-        finally senderPersistentActor ! evt // sender is persistentActor
+        finally senderPersistentActor() ! evt // sender is persistentActor
       case evt @ SaveSnapshotFailure(metadata, _) =>
         try {
           tryReceivePluginInternal(evt)
diff --git a/akka-persistence/src/test/scala/akka/persistence/PersistentActorBoundedStashingSpec.scala b/akka-persistence/src/test/scala/akka/persistence/PersistentActorBoundedStashingSpec.scala
index 8f2cc14948..23f64329fe 100644
--- a/akka-persistence/src/test/scala/akka/persistence/PersistentActorBoundedStashingSpec.scala
+++ b/akka-persistence/src/test/scala/akka/persistence/PersistentActorBoundedStashingSpec.scala
@@ -70,7 +70,7 @@ class SteppingInMemPersistentActorBoundedStashingSpec(strategyConfig: String)
     with BeforeAndAfterEach
     with ImplicitSender {
 
-  override def atStartup: Unit = {
+  override def atStartup(): Unit = {
     system.eventStream.publish(Mute(EventFilter.warning(pattern = ".*received dead letter from.*Cmd.*")))
   }
 
diff --git a/akka-persistence/src/test/scala/akka/persistence/PersistentActorJournalProtocolSpec.scala b/akka-persistence/src/test/scala/akka/persistence/PersistentActorJournalProtocolSpec.scala
index e14a74bd7c..ba969d9522 100644
--- a/akka-persistence/src/test/scala/akka/persistence/PersistentActorJournalProtocolSpec.scala
+++ b/akka-persistence/src/test/scala/akka/persistence/PersistentActorJournalProtocolSpec.scala
@@ -78,7 +78,7 @@ akka.persistence.snapshot-store.plugin = "akka.persistence.no-snapshot-store"
 }
 
 object JournalPuppet extends ExtensionId[JournalProbe] with ExtensionIdProvider {
-  override def lookup() = JournalPuppet
+  override def lookup = JournalPuppet
 
   override def createExtension(system: ExtendedActorSystem): JournalProbe =
     new JournalProbe()(system)
diff --git a/akka-persistence/src/test/scala/akka/persistence/TimerPersistentActorSpec.scala b/akka-persistence/src/test/scala/akka/persistence/TimerPersistentActorSpec.scala
index fad5a7b62d..b009455135 100644
--- a/akka-persistence/src/test/scala/akka/persistence/TimerPersistentActorSpec.scala
+++ b/akka-persistence/src/test/scala/akka/persistence/TimerPersistentActorSpec.scala
@@ -6,7 +6,6 @@ package akka.persistence
 
 import scala.concurrent.duration._
 import scala.runtime.BoxedUnit
-import scala.runtime.BoxedUnit
 
 import com.typesafe.config.ConfigFactory
 
diff --git a/akka-remote-tests/src/multi-jvm/scala/akka/remote/AttemptSysMsgRedeliverySpec.scala b/akka-remote-tests/src/multi-jvm/scala/akka/remote/AttemptSysMsgRedeliverySpec.scala
index 3d6bba19c2..486cfcf75d 100644
--- a/akka-remote-tests/src/multi-jvm/scala/akka/remote/AttemptSysMsgRedeliverySpec.scala
+++ b/akka-remote-tests/src/multi-jvm/scala/akka/remote/AttemptSysMsgRedeliverySpec.scala
@@ -50,7 +50,7 @@ class ArteryAttemptSysMsgRedeliveryMultiJvmNode3
 object AttemptSysMsgRedeliverySpec {
   class Echo extends Actor {
     def receive = {
-      case m => sender ! m
+      case m => sender() ! m
     }
   }
 }
diff --git a/akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteQuarantinePiercingSpec.scala b/akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteQuarantinePiercingSpec.scala
index f9306a49fa..03998aa939 100644
--- a/akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteQuarantinePiercingSpec.scala
+++ b/akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteQuarantinePiercingSpec.scala
@@ -11,7 +11,6 @@ import com.typesafe.config.ConfigFactory
 
 import akka.actor._
 import akka.remote.testconductor.RoleName
-import akka.remote.testconductor.RoleName
 import akka.remote.testkit.MultiNodeConfig
 import akka.testkit._
 
diff --git a/akka-remote/src/main/scala/akka/remote/DeadlineFailureDetector.scala b/akka-remote/src/main/scala/akka/remote/DeadlineFailureDetector.scala
index ea67c146f1..e82cff4059 100644
--- a/akka-remote/src/main/scala/akka/remote/DeadlineFailureDetector.scala
+++ b/akka-remote/src/main/scala/akka/remote/DeadlineFailureDetector.scala
@@ -4,7 +4,6 @@
 
 package akka.remote
 
-import scala.concurrent.duration._
 import scala.concurrent.duration.Duration
 import scala.concurrent.duration.FiniteDuration
 
diff --git a/akka-remote/src/main/scala/akka/remote/RemoteDeployer.scala b/akka-remote/src/main/scala/akka/remote/RemoteDeployer.scala
index 0a5b4f9d30..cabfbdb9ab 100644
--- a/akka-remote/src/main/scala/akka/remote/RemoteDeployer.scala
+++ b/akka-remote/src/main/scala/akka/remote/RemoteDeployer.scala
@@ -9,7 +9,6 @@ import com.typesafe.config._
 import akka.ConfigurationException
 import akka.actor._
 import akka.japi.Util.immutableSeq
-import akka.remote.routing._
 import akka.remote.routing.RemoteRouterConfig
 import akka.routing._
 import akka.routing.Pool
diff --git a/akka-remote/src/main/scala/akka/remote/Remoting.scala b/akka-remote/src/main/scala/akka/remote/Remoting.scala
index 41dff1bad7..04addaa647 100644
--- a/akka-remote/src/main/scala/akka/remote/Remoting.scala
+++ b/akka-remote/src/main/scala/akka/remote/Remoting.scala
@@ -55,7 +55,7 @@ private[akka] final case class RARP(provider: RemoteActorRefProvider) extends Ex
  */
 private[akka] object RARP extends ExtensionId[RARP] with ExtensionIdProvider {
 
-  override def lookup() = RARP
+  override def lookup = RARP
 
   override def createExtension(system: ExtendedActorSystem) = RARP(system.provider.asInstanceOf[RemoteActorRefProvider])
 }
diff --git a/akka-remote/src/main/scala/akka/remote/artery/RemotingFlightRecorder.scala b/akka-remote/src/main/scala/akka/remote/artery/RemotingFlightRecorder.scala
index 41fefdf3cf..b9aa54ec8d 100644
--- a/akka-remote/src/main/scala/akka/remote/artery/RemotingFlightRecorder.scala
+++ b/akka-remote/src/main/scala/akka/remote/artery/RemotingFlightRecorder.scala
@@ -27,7 +27,7 @@ object RemotingFlightRecorder extends ExtensionId[RemotingFlightRecorder] with E
       "akka.remote.artery.jfr.JFRRemotingFlightRecorder",
       NoOpRemotingFlightRecorder)
 
-  override def lookup(): ExtensionId[_ <: Extension] = this
+  override def lookup: ExtensionId[_ <: Extension] = this
 }
 
 /**
diff --git a/akka-remote/src/test/scala/akka/remote/artery/BindCanonicalAddressSpec.scala b/akka-remote/src/test/scala/akka/remote/artery/BindCanonicalAddressSpec.scala
index 4976d031a4..10f964b531 100644
--- a/akka-remote/src/test/scala/akka/remote/artery/BindCanonicalAddressSpec.scala
+++ b/akka-remote/src/test/scala/akka/remote/artery/BindCanonicalAddressSpec.scala
@@ -30,7 +30,7 @@ trait BindCanonicalAddressBehaviors {
 
       implicit val sys = ActorSystem("sys", config.withFallback(commonConfig))
 
-      getInternal should contain(getExternal())
+      getInternal() should contain(getExternal())
       Await.result(sys.terminate(), Duration.Inf)
     }
 
@@ -44,7 +44,7 @@ trait BindCanonicalAddressBehaviors {
 
       implicit val sys = ActorSystem("sys", config.withFallback(commonConfig))
 
-      getExternal should ===(address.toAkkaAddress("akka"))
+      getExternal() should ===(address.toAkkaAddress("akka"))
       // May have selected the same random port - bind another in that case while the other still has the canonical port
       val internals =
         if (getInternal().collect { case Address(_, _, _, Some(port)) => port }.toSeq.contains(address.getPort)) {
@@ -82,8 +82,8 @@ trait BindCanonicalAddressBehaviors {
 
       implicit val sys = ActorSystem("sys", config.withFallback(commonConfig))
 
-      getExternal should ===(address.toAkkaAddress("akka"))
-      getInternal should contain(address.toAkkaAddress("akka"))
+      getExternal() should ===(address.toAkkaAddress("akka"))
+      getInternal() should contain(address.toAkkaAddress("akka"))
     }
 
     "bind to all interfaces" in {
diff --git a/akka-remote/src/test/scala/akka/remote/artery/compress/CompressionIntegrationSpec.scala b/akka-remote/src/test/scala/akka/remote/artery/compress/CompressionIntegrationSpec.scala
index 199591739e..d08f197e26 100644
--- a/akka-remote/src/test/scala/akka/remote/artery/compress/CompressionIntegrationSpec.scala
+++ b/akka-remote/src/test/scala/akka/remote/artery/compress/CompressionIntegrationSpec.scala
@@ -6,7 +6,6 @@ package akka.remote.artery.compress
 
 import scala.concurrent.duration._
 
-import com.typesafe.config.ConfigFactory
 import com.typesafe.config.ConfigFactory
 
 import akka.actor._
diff --git a/akka-remote/src/test/scala/akka/remote/classic/transport/netty/NettyTransportSpec.scala b/akka-remote/src/test/scala/akka/remote/classic/transport/netty/NettyTransportSpec.scala
index 645fffb877..ddb20c71bd 100644
--- a/akka-remote/src/test/scala/akka/remote/classic/transport/netty/NettyTransportSpec.scala
+++ b/akka-remote/src/test/scala/akka/remote/classic/transport/netty/NettyTransportSpec.scala
@@ -55,7 +55,7 @@ class NettyTransportSpec extends AnyWordSpec with Matchers with BindBehavior {
         """)
       implicit val sys = ActorSystem("sys", bindConfig.withFallback(commonConfig))
 
-      getInternal should contain(getExternal.withProtocol("tcp"))
+      getInternal() should contain(getExternal().withProtocol("tcp"))
 
       Await.result(sys.terminate(), Duration.Inf)
     }
@@ -74,8 +74,8 @@ class NettyTransportSpec extends AnyWordSpec with Matchers with BindBehavior {
         """)
         implicit val sys = ActorSystem("sys", bindConfig.withFallback(commonConfig))
 
-        getExternal should ===(address.toAkkaAddress("akka.tcp"))
-        getInternal should not contain address.toAkkaAddress("tcp")
+        getExternal() should ===(address.toAkkaAddress("akka.tcp"))
+        getInternal() should not contain address.toAkkaAddress("tcp")
 
         Await.result(sys.terminate(), Duration.Inf)
       } finally {
@@ -102,8 +102,8 @@ class NettyTransportSpec extends AnyWordSpec with Matchers with BindBehavior {
         """)
       implicit val sys = ActorSystem("sys", bindConfig.withFallback(commonConfig))
 
-      getExternal should ===(address.toAkkaAddress("akka.tcp"))
-      getInternal should contain(address.toAkkaAddress("tcp"))
+      getExternal() should ===(address.toAkkaAddress("akka.tcp"))
+      getInternal() should contain(address.toAkkaAddress("tcp"))
 
       Await.result(sys.terminate(), Duration.Inf)
     }
@@ -147,8 +147,8 @@ trait BindBehavior {
         """)
       implicit val sys = ActorSystem("sys", bindConfig.withFallback(commonConfig))
 
-      getExternal should ===(address.toAkkaAddress(s"akka.tcp"))
-      getInternal should contain(address.toAkkaAddress("tcp"))
+      getExternal() should ===(address.toAkkaAddress(s"akka.tcp"))
+      getInternal() should contain(address.toAkkaAddress("tcp"))
 
       Await.result(sys.terminate(), Duration.Inf)
     }
@@ -179,8 +179,8 @@ trait BindBehavior {
         """)
       implicit val sys = ActorSystem("sys", bindConfig.withFallback(commonConfig))
 
-      getExternal should ===(address.toAkkaAddress(s"akka.tcp"))
-      getInternal should contain(bindAddress.toAkkaAddress("tcp"))
+      getExternal() should ===(address.toAkkaAddress(s"akka.tcp"))
+      getInternal() should contain(bindAddress.toAkkaAddress("tcp"))
 
       Await.result(sys.terminate(), Duration.Inf)
     }
diff --git a/akka-stream-testkit/src/test/scala/akka/stream/testkit/ScriptedTest.scala b/akka-stream-testkit/src/test/scala/akka/stream/testkit/ScriptedTest.scala
index 06fe748099..2e6250471a 100644
--- a/akka-stream-testkit/src/test/scala/akka/stream/testkit/ScriptedTest.scala
+++ b/akka-stream-testkit/src/test/scala/akka/stream/testkit/ScriptedTest.scala
@@ -4,7 +4,6 @@
 
 package akka.stream.testkit
 
-import java.util.concurrent.ThreadLocalRandom
 import java.util.concurrent.ThreadLocalRandom
 
 import scala.annotation.tailrec
@@ -19,7 +18,6 @@ import akka.actor.ActorSystem
 import akka.stream.ActorMaterializerSettings
 import akka.stream.Materializer
 import akka.stream.SystemMaterializer
-import akka.stream.SystemMaterializer
 import akka.stream.scaladsl.Flow
 import akka.stream.scaladsl.Sink
 import akka.stream.scaladsl.Source
diff --git a/akka-stream-tests/src/test/scala/akka/stream/ActorMaterializerSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/ActorMaterializerSpec.scala
index aa377df3b0..0584efdc08 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/ActorMaterializerSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/ActorMaterializerSpec.scala
@@ -29,7 +29,7 @@ object IndirectMaterializerCreation extends ExtensionId[IndirectMaterializerCrea
   def createExtension(system: ExtendedActorSystem): IndirectMaterializerCreation =
     new IndirectMaterializerCreation(system)
 
-  def lookup(): ExtensionId[IndirectMaterializerCreation] = this
+  def lookup: ExtensionId[IndirectMaterializerCreation] = this
 }
 
 @silent
diff --git a/akka-stream-tests/src/test/scala/akka/stream/FusingSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/FusingSpec.scala
index f5d646055d..cb9eccee5b 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/FusingSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/FusingSpec.scala
@@ -102,7 +102,7 @@ class FusingSpec extends StreamSpec {
     }
 
     "propagate downstream errors through async boundary" in {
-      val promise = Promise[Done]
+      val promise = Promise[Done]()
       val slowInitSrc = UnfoldResourceNoAsyncBoundry(
         () => { Await.result(promise.future, 1.minute); () },
         (_: Unit) => Some(1),
@@ -132,7 +132,7 @@ class FusingSpec extends StreamSpec {
     }
 
     "propagate 'parallel' errors through async boundary via a common downstream" in {
-      val promise = Promise[Done]
+      val promise = Promise[Done]()
       val slowInitSrc = UnfoldResourceNoAsyncBoundry(
         () => { Await.result(promise.future, 1.minute); () },
         (_: Unit) => Some(1),
diff --git a/akka-stream-tests/src/test/scala/akka/stream/SystemMaterializerSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/SystemMaterializerSpec.scala
index ef5e9aa02b..a10080d074 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/SystemMaterializerSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/SystemMaterializerSpec.scala
@@ -39,7 +39,7 @@ class SystemMaterializerEagerStartupSpec extends StreamSpec {
   "The SystemMaterializer" must {
 
     "be eagerly started on system startup" in {
-      system.hasExtension(SystemMaterializer.lookup()) should ===(true)
+      system.hasExtension(SystemMaterializer.lookup) should ===(true)
     }
   }
 
diff --git a/akka-stream-tests/src/test/scala/akka/stream/impl/fusing/LifecycleInterpreterSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/impl/fusing/LifecycleInterpreterSpec.scala
index 4683b7ea68..41862ca0c5 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/impl/fusing/LifecycleInterpreterSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/impl/fusing/LifecycleInterpreterSpec.scala
@@ -101,7 +101,7 @@ class LifecycleInterpreterSpec extends StreamSpec with GraphInterpreterSpecKit {
       lastEvents() should ===(Set())
 
       upstream.onComplete()
-      lastEvents should ===(Set(OnComplete))
+      lastEvents() should ===(Set(OnComplete))
     }
 
     "postStop when pushAndFinish called if upstream completes with pushAndFinish" in new OneBoundedSetup[String](
diff --git a/akka-stream-tests/src/test/scala/akka/stream/io/TcpSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/io/TcpSpec.scala
index af5d203fcd..772dc6263d 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/io/TcpSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/io/TcpSpec.scala
@@ -15,7 +15,6 @@ import scala.concurrent.Future
 import scala.concurrent.Promise
 import scala.concurrent.duration._
 
-import com.github.ghik.silencer.silent
 import com.github.ghik.silencer.silent
 import com.typesafe.config.Config
 import com.typesafe.config.ConfigFactory
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFlatMapPrefixSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFlatMapPrefixSpec.scala
index 92ddf04786..0e6d6eff76 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFlatMapPrefixSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFlatMapPrefixSpec.scala
@@ -47,7 +47,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 2)
         suffixF.futureValue should ===(2 until 10)
@@ -60,7 +60,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 10)
         suffixF.futureValue should be(empty)
@@ -73,7 +73,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 10)
         suffixF.futureValue should be(empty)
@@ -87,7 +87,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           .take(10)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 10)
         suffixF.futureValue should ===(10 until 20)
@@ -100,7 +100,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .to(Sink.ignore)
           .withAttributes(attributes)
-          .run
+          .run()
 
         val ex = suffixF.failed.futureValue
         ex.getCause should not be null
@@ -117,7 +117,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.ignore)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
         prefixF.futureValue should ===(0 until 10)
         val ex = suffixF.failed.futureValue
         ex should ===(TE("don't like 15 either!"))
@@ -203,7 +203,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 4)
         suffixF.futureValue should be(empty)
@@ -221,7 +221,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 4)
         suffixF.futureValue should be(empty)
@@ -234,7 +234,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.futureValue should ===(0 until 4)
         suffixF.futureValue should ===(11 :: 12 :: Nil)
@@ -247,7 +247,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         prefixF.failed.futureValue should be(a[NeverMaterializedException])
         prefixF.failed.futureValue.getCause should ===(TE("boom-bada-bang (4)"))
@@ -265,7 +265,7 @@ class FlowFlatMapPrefixSpec extends StreamSpec {
           }(Keep.right)
           .toMat(Sink.seq)(Keep.both)
           .withAttributes(attributes)
-          .run
+          .run()
 
         suffixF.futureValue should be(empty)
         val (prefix, suffix) = prefixAndTailF.futureValue
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFutureFlowSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFutureFlowSpec.scala
index f3abc71c98..04fc52603a 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFutureFlowSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowFutureFlowSpec.scala
@@ -48,7 +48,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "work in the simple case with a late future" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -85,7 +85,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "fail properly when future is late completed failed future" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -126,7 +126,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "handle upstream failure when future is late-completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10WithFailure()(5)
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -166,7 +166,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "propagate upstream failure when future is late-completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10WithFailure()(5)
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -210,7 +210,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "handle early upstream error when flow future is late-completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = Source
           .failed(TE("not today my friend"))
           .viaMat {
@@ -257,7 +257,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "handle closed downstream when flow future is late completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]
+        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]()
         val (fSeq1, fSeq2) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -305,7 +305,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "handle early downstream failure when flow future is late completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]
+        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]()
         val (fSeq1, fSeq2) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -351,7 +351,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "handle early upstream completion when flow future is late-completed" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = Source
           .empty[Int]
           .viaMat {
@@ -389,7 +389,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "fails properly on materialization failure with a late future" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -429,7 +429,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "propagate flow failures with a late future" in assertAllStagesStopped {
-        val prFlow = Promise[Flow[Int, Int, NotUsed]]
+        val prFlow = Promise[Flow[Int, Int, NotUsed]]()
         val (fNotUsed, fSeq) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
@@ -471,7 +471,7 @@ class FlowFutureFlowSpec extends StreamSpec {
       }
 
       "allow flow to handle downstream completion with a late future" in assertAllStagesStopped {
-        val pr = Promise[Flow[Int, Int, Future[Seq[Int]]]]
+        val pr = Promise[Flow[Int, Int, Future[Seq[Int]]]]()
         val (fSeq1, fSeq2) = src10()
           .viaMat {
             Flow.futureFlow(pr.future)
@@ -494,7 +494,7 @@ class FlowFutureFlowSpec extends StreamSpec {
 
       "abrupt termination before future completion" in assertAllStagesStopped {
         val mat = Materializer(system)
-        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]
+        val prFlow = Promise[Flow[Int, Int, Future[collection.immutable.Seq[Int]]]]()
         val (fSeq1, fSeq2) = src10()
           .viaMat {
             Flow.futureFlow(prFlow.future)
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowMapAsyncUnorderedSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowMapAsyncUnorderedSpec.scala
index 5009bd1384..fd4bf9ad4e 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowMapAsyncUnorderedSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowMapAsyncUnorderedSpec.scala
@@ -252,7 +252,7 @@ class FlowMapAsyncUnorderedSpec extends StreamSpec {
       }
       val result = Source(List(1, 2, 3)).via(flow).runWith(Sink.seq)
 
-      result.futureValue should contain only ("1", "3")
+      result.futureValue should contain.only("1", "3")
     }
 
     "continue emitting after a sequence of nulls" in {
@@ -263,7 +263,7 @@ class FlowMapAsyncUnorderedSpec extends StreamSpec {
 
       val result = Source(0 to 102).via(flow).runWith(Sink.seq)
 
-      result.futureValue should contain only ("0", "100", "101", "102")
+      result.futureValue should contain.only("0", "100", "101", "102")
     }
 
     "complete without emitting any element after a sequence of nulls only" in {
@@ -293,7 +293,7 @@ class FlowMapAsyncUnorderedSpec extends StreamSpec {
 
       val result = Source(List(1, 2, 3)).via(flow).runWith(Sink.seq)
 
-      result.futureValue should contain only ("1", "3")
+      result.futureValue should contain.only("1", "3")
     }
 
     "handle cancel properly" in assertAllStagesStopped {
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/QueueSourceSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/QueueSourceSpec.scala
index 6107f8e5a7..9c3ee03ad9 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/QueueSourceSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/QueueSourceSpec.scala
@@ -127,7 +127,7 @@ class QueueSourceSpec extends StreamSpec {
       val queue = Source.queue(0, OverflowStrategy.dropHead).to(Sink.fromSubscriber(s)).run()
       val sub = s.expectSubscription()
 
-      queue.watchCompletion.pipeTo(testActor)
+      queue.watchCompletion().pipeTo(testActor)
       queue.offer(1).pipeTo(testActor)
       expectNoMessage(pause)
 
@@ -138,7 +138,7 @@ class QueueSourceSpec extends StreamSpec {
 
     "fail future immediately when stream is already cancelled" in assertAllStagesStopped {
       val queue = Source.queue[Int](0, OverflowStrategy.dropHead).to(Sink.cancelled).run()
-      queue.watchCompletion.futureValue
+      queue.watchCompletion().futureValue
       queue.offer(1).failed.futureValue shouldBe a[StreamDetachedException]
     }
 
@@ -282,7 +282,7 @@ class QueueSourceSpec extends StreamSpec {
       sourceQueue1.offer("hello")
       mat1subscriber.expectNext("hello")
       mat1subscriber.cancel()
-      sourceQueue1.watchCompletion.pipeTo(testActor)
+      sourceQueue1.watchCompletion().pipeTo(testActor)
       expectMsg(Done)
 
       sourceQueue2.watchCompletion().isCompleted should ===(false)
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/RestartSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/RestartSpec.scala
index 0ee74dd84c..48ece36f03 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/RestartSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/RestartSpec.scala
@@ -587,7 +587,7 @@ class RestartSpec extends StreamSpec(Map("akka.test.single-expect-default" -> "1
       source.sendNext("cancel")
       // This will complete the flow in probe and cancel the flow out probe
       flowInProbe.request(2)
-      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain only ("in complete", "out complete")
+      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain.only("in complete", "out complete")
 
       // and it should restart
       source.sendNext("c")
@@ -611,7 +611,7 @@ class RestartSpec extends StreamSpec(Map("akka.test.single-expect-default" -> "1
 
       // This will complete the flow in probe and cancel the flow out probe
       flowInProbe.request(2)
-      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain only ("in complete", "out complete")
+      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain.only("in complete", "out complete")
 
       // and it should restart
       source.sendNext("c")
@@ -661,7 +661,7 @@ class RestartSpec extends StreamSpec(Map("akka.test.single-expect-default" -> "1
       source.sendNext("cancel")
       // This will complete the flow in probe and cancel the flow out probe
       flowInProbe.request(2)
-      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain only ("in complete", "out complete")
+      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain.only("in complete", "out complete")
 
       source.sendNext("c")
       flowInProbe.request(1)
@@ -726,7 +726,7 @@ class RestartSpec extends StreamSpec(Map("akka.test.single-expect-default" -> "1
 
       // This will complete the flow in probe and cancel the flow out probe
       flowInProbe.request(2)
-      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain only ("in complete", "out complete")
+      Seq(flowInProbe.expectNext(), flowInProbe.expectNext()) should contain.only("in complete", "out complete")
 
       // and it should restart
       sink.request(1)
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/SinkForeachAsyncSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/SinkForeachAsyncSpec.scala
index 5461956965..d2f3729268 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/SinkForeachAsyncSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/SinkForeachAsyncSpec.scala
@@ -103,7 +103,7 @@ class SinkForeachAsyncSpec extends StreamSpec {
       }
 
       val p =
-        Source(List(one _, two _, three _, four _)).runWith(sink)
+        Source(List(() => one, () => two, () => three, () => four)).runWith(sink)
 
       latch(1).countDown()
       probe.expectMsg(1)
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/UnfoldResourceAsyncSourceSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/UnfoldResourceAsyncSourceSpec.scala
index 6b1102f4a4..c274165312 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/UnfoldResourceAsyncSourceSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/UnfoldResourceAsyncSourceSpec.scala
@@ -80,7 +80,7 @@ class UnfoldResourceAsyncSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
 
       val probe = TestSubscriber.probe[Int]()
       Source
-        .unfoldResourceAsync[Int, ResourceDummy[Int]](resource.create _, _.read, _.close())
+        .unfoldResourceAsync[Int, ResourceDummy[Int]](() => resource.create, _.read, _.close())
         .runWith(Sink.fromSubscriber(probe))
 
       probe.request(1)
@@ -106,7 +106,7 @@ class UnfoldResourceAsyncSourceSpec extends StreamSpec(UnboundedMailboxConfig) {
       val resource = new ResourceDummy[Int](1 :: Nil, firstReadFuture = firstRead.future)
 
       Source
-        .unfoldResourceAsync[Int, ResourceDummy[Int]](resource.create _, _.read, _.close())
+        .unfoldResourceAsync[Int, ResourceDummy[Int]](() => resource.create, _.read, _.close())
         .runWith(Sink.fromSubscriber(probe))
 
       probe.request(1L)
diff --git a/akka-stream/src/main/scala/akka/stream/Attributes.scala b/akka-stream/src/main/scala/akka/stream/Attributes.scala
index 76af695648..79428794d5 100644
--- a/akka-stream/src/main/scala/akka/stream/Attributes.scala
+++ b/akka-stream/src/main/scala/akka/stream/Attributes.scala
@@ -12,8 +12,6 @@ import scala.annotation.tailrec
 import scala.compat.java8.OptionConverters._
 import scala.concurrent.duration.FiniteDuration
 import scala.reflect.{ classTag, ClassTag }
-import akka.japi.function
-import java.time.Duration
 
 import akka.annotation.ApiMayChange
 import akka.annotation.DoNotInherit
@@ -21,13 +19,8 @@ import akka.annotation.InternalApi
 import akka.event.Logging
 import akka.japi.function
 import akka.stream.impl.TraversalBuilder
-import akka.util.JavaDurationConverters._
-import akka.util.JavaDurationConverters._
-
-import scala.compat.java8.OptionConverters._
 import akka.util.{ ByteString, OptionVal }
-
-import scala.concurrent.duration.FiniteDuration
+import akka.util.JavaDurationConverters._
 
 /**
  * Holds attributes which can be used to alter [[akka.stream.scaladsl.Flow]] / [[akka.stream.javadsl.Flow]]
diff --git a/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala b/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
index 482254c0ba..7feff97654 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/ActorMaterializerImpl.scala
@@ -176,7 +176,7 @@ private[akka] class SubFusingActorMaterializerImpl(
 @InternalApi private[akka] object FlowNames extends ExtensionId[FlowNames] with ExtensionIdProvider {
   override def get(system: ActorSystem): FlowNames = super.get(system)
   override def get(system: ClassicActorSystemProvider): FlowNames = super.get(system)
-  override def lookup() = FlowNames
+  override def lookup = FlowNames
   override def createExtension(system: ExtendedActorSystem): FlowNames = new FlowNames
 }
 
diff --git a/akka-stream/src/main/scala/akka/stream/impl/FanIn.scala b/akka-stream/src/main/scala/akka/stream/impl/FanIn.scala
index 920aad53dd..c13e86baa6 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/FanIn.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/FanIn.scala
@@ -250,7 +250,7 @@ import akka.util.unused
           }
           registerCompleted(id)
           inputs(id).subreceive(ActorSubscriberMessage.OnComplete)
-          if (!receivedInput && isAllCompleted) onCompleteWhenNoInput()
+          if (!receivedInput && isAllCompleted()) onCompleteWhenNoInput()
         case OnError(id, e) =>
           onError(id, e)
       })
diff --git a/akka-stream/src/main/scala/akka/stream/impl/PhasedFusingActorMaterializer.scala b/akka-stream/src/main/scala/akka/stream/impl/PhasedFusingActorMaterializer.scala
index 0b87a43d36..075ba922d6 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/PhasedFusingActorMaterializer.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/PhasedFusingActorMaterializer.scala
@@ -9,7 +9,6 @@ import java.util.concurrent.atomic.AtomicBoolean
 
 import scala.collection.immutable.Map
 import scala.concurrent.ExecutionContextExecutor
-import scala.concurrent.ExecutionContextExecutor
 import scala.concurrent.duration.FiniteDuration
 
 import com.github.ghik.silencer.silent
@@ -45,7 +44,6 @@ import akka.stream.stage.GraphStageLogic
 import akka.stream.stage.InHandler
 import akka.stream.stage.OutHandler
 import akka.util.OptionVal
-import akka.util.OptionVal
 
 /**
  * INTERNAL API
diff --git a/akka-stream/src/main/scala/akka/stream/impl/SubscriberManagement.scala b/akka-stream/src/main/scala/akka/stream/impl/SubscriberManagement.scala
index f45ed42485..3306c85993 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/SubscriberManagement.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/SubscriberManagement.scala
@@ -6,7 +6,6 @@ package akka.stream.impl
 
 import scala.annotation.tailrec
 
-import SubscriberManagement.ShutDown
 import org.reactivestreams.{ Subscriber, Subscription }
 
 /**
diff --git a/akka-stream/src/main/scala/akka/stream/impl/fusing/FlatMapPrefix.scala b/akka-stream/src/main/scala/akka/stream/impl/fusing/FlatMapPrefix.scala
index 80f005093c..babd72d66e 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/fusing/FlatMapPrefix.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/fusing/FlatMapPrefix.scala
@@ -31,7 +31,7 @@ import akka.util.OptionVal
       inheritedAttributes
         .mandatoryAttribute[Attributes.NestedMaterializationCancellationPolicy]
         .propagateToNestedMaterialization
-    val matPromise = Promise[M]
+    val matPromise = Promise[M]()
     val logic = new GraphStageLogic(shape) with InHandler with OutHandler {
       val accumulated = collection.mutable.Buffer.empty[In]
 
diff --git a/akka-stream/src/main/scala/akka/stream/impl/fusing/FutureFlow.scala b/akka-stream/src/main/scala/akka/stream/impl/fusing/FutureFlow.scala
index c3c99cc8c1..188094ce8e 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/fusing/FutureFlow.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/fusing/FutureFlow.scala
@@ -26,7 +26,7 @@ import scala.util.{ Failure, Success, Try }
       inheritedAttributes
         .mandatoryAttribute[Attributes.NestedMaterializationCancellationPolicy]
         .propagateToNestedMaterialization
-    val innerMatValue = Promise[M]
+    val innerMatValue = Promise[M]()
     val logic = new GraphStageLogic(shape) {
 
       //seems like we must set handlers BEFORE preStart
diff --git a/akka-stream/src/main/scala/akka/stream/impl/fusing/StreamOfStreams.scala b/akka-stream/src/main/scala/akka/stream/impl/fusing/StreamOfStreams.scala
index c90a2f9a6d..32afa92aca 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/fusing/StreamOfStreams.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/fusing/StreamOfStreams.scala
@@ -364,7 +364,7 @@ import akka.util.ccompat.JavaConverters._
         }
 
       private def runSubstream(key: K, value: T): Unit = {
-        val substreamSource = new SubstreamSource("GroupBySource " + nextId, key, value)
+        val substreamSource = new SubstreamSource("GroupBySource " + nextId(), key, value)
         activeSubstreamsMap.put(key, substreamSource)
         firstPushCounter += 1
         if (isAvailable(out)) {
diff --git a/akka-stream/src/main/scala/akka/stream/impl/io/TLSActor.scala b/akka-stream/src/main/scala/akka/stream/impl/io/TLSActor.scala
index ca75256f65..e9ead4b7c8 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/io/TLSActor.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/io/TLSActor.scala
@@ -294,7 +294,7 @@ import akka.util.ByteString
     } else if (inboundState.isReady) {
       transportInChoppingBlock.chopInto(transportInBuffer)
       try {
-        doUnwrap()
+        doUnwrap(ignoreOutput = false)
         true
       } catch {
         case ex: SSLException =>
@@ -383,7 +383,7 @@ import akka.util.ByteString
   }
 
   @tailrec
-  private def doUnwrap(ignoreOutput: Boolean = false): Unit = {
+  private def doUnwrap(ignoreOutput: Boolean): Unit = {
     val result = engine.unwrap(transportInBuffer, userOutBuffer)
     if (ignoreOutput) userOutBuffer.clear()
     lastHandshakeStatus = result.getHandshakeStatus
@@ -403,7 +403,7 @@ import akka.util.ByteString
             handshakeFinished()
             transportInChoppingBlock.putBack(transportInBuffer)
           case _ =>
-            if (transportInBuffer.hasRemaining) doUnwrap()
+            if (transportInBuffer.hasRemaining) doUnwrap(ignoreOutput = false)
             else flushToUser()
         }
       case CLOSED =>
diff --git a/akka-stream/src/main/scala/akka/stream/impl/streamref/StreamRefsMaster.scala b/akka-stream/src/main/scala/akka/stream/impl/streamref/StreamRefsMaster.scala
index 52272ef98b..c2d80d4fe4 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/streamref/StreamRefsMaster.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/streamref/StreamRefsMaster.scala
@@ -16,7 +16,7 @@ private[stream] object StreamRefsMaster extends ExtensionId[StreamRefsMaster] wi
   override def createExtension(system: ExtendedActorSystem): StreamRefsMaster =
     new StreamRefsMaster
 
-  override def lookup(): StreamRefsMaster.type = this
+  override def lookup: StreamRefsMaster.type = this
 
   override def get(system: ActorSystem): StreamRefsMaster = super.get(system)
   override def get(system: ClassicActorSystemProvider): StreamRefsMaster = super.get(system)
diff --git a/akka-stream/src/main/scala/akka/stream/javadsl/Tcp.scala b/akka-stream/src/main/scala/akka/stream/javadsl/Tcp.scala
index f17b12202f..c3e54b68e6 100644
--- a/akka-stream/src/main/scala/akka/stream/javadsl/Tcp.scala
+++ b/akka-stream/src/main/scala/akka/stream/javadsl/Tcp.scala
@@ -131,7 +131,7 @@ object Tcp extends ExtensionId[Tcp] with ExtensionIdProvider {
 
   override def get(system: ClassicActorSystemProvider): Tcp = super.get(system)
 
-  def lookup() = Tcp
+  def lookup = Tcp
 
   def createExtension(system: ExtendedActorSystem): Tcp = new Tcp(system)
 }
diff --git a/akka-stream/src/main/scala/akka/stream/scaladsl/Tcp.scala b/akka-stream/src/main/scala/akka/stream/scaladsl/Tcp.scala
index ba2398df33..1326b19487 100644
--- a/akka-stream/src/main/scala/akka/stream/scaladsl/Tcp.scala
+++ b/akka-stream/src/main/scala/akka/stream/scaladsl/Tcp.scala
@@ -12,7 +12,6 @@ import javax.net.ssl.SSLSession
 
 import scala.collection.immutable
 import scala.concurrent.Future
-import scala.concurrent.duration._
 import scala.concurrent.duration.Duration
 import scala.concurrent.duration.FiniteDuration
 import scala.util.Success
@@ -85,7 +84,7 @@ object Tcp extends ExtensionId[Tcp] with ExtensionIdProvider {
   override def get(system: ActorSystem): Tcp = super.get(system)
   override def get(system: ClassicActorSystemProvider): Tcp = super.get(system)
 
-  def lookup() = Tcp
+  def lookup = Tcp
 
   def createExtension(system: ExtendedActorSystem): Tcp = new Tcp(system)
 
diff --git a/akka-stream/src/main/scala/com/typesafe/sslconfig/akka/AkkaSSLConfig.scala b/akka-stream/src/main/scala/com/typesafe/sslconfig/akka/AkkaSSLConfig.scala
index 3aad9c62d6..d5cf1c77cd 100644
--- a/akka-stream/src/main/scala/com/typesafe/sslconfig/akka/AkkaSSLConfig.scala
+++ b/akka-stream/src/main/scala/com/typesafe/sslconfig/akka/AkkaSSLConfig.scala
@@ -26,7 +26,7 @@ object AkkaSSLConfig extends ExtensionId[AkkaSSLConfig] with ExtensionIdProvider
   override def get(system: ClassicActorSystemProvider): AkkaSSLConfig = super.get(system)
   def apply()(implicit system: ActorSystem): AkkaSSLConfig = super.apply(system)
 
-  override def lookup() = AkkaSSLConfig
+  override def lookup = AkkaSSLConfig
 
   override def createExtension(system: ExtendedActorSystem): AkkaSSLConfig =
     new AkkaSSLConfig(system, defaultSSLConfigSettings(system))
diff --git a/akka-testkit/src/test/scala/akka/testkit/AkkaSpec.scala b/akka-testkit/src/test/scala/akka/testkit/AkkaSpec.scala
index 498f26f91c..c71c29dbcf 100644
--- a/akka-testkit/src/test/scala/akka/testkit/AkkaSpec.scala
+++ b/akka-testkit/src/test/scala/akka/testkit/AkkaSpec.scala
@@ -78,12 +78,12 @@ abstract class AkkaSpec(_system: ActorSystem)
 
   override val invokeBeforeAllAndAfterAllEvenIfNoTestsAreExpected = true
 
-  final override def beforeAll: Unit = {
+  final override def beforeAll(): Unit = {
     startCoroner()
     atStartup()
   }
 
-  final override def afterAll: Unit = {
+  final override def afterAll(): Unit = {
     beforeTermination()
     shutdown()
     afterTermination()
diff --git a/akka-testkit/src/test/scala/akka/testkit/DefaultTimeoutSpec.scala b/akka-testkit/src/test/scala/akka/testkit/DefaultTimeoutSpec.scala
index 20bb50f0f3..a0d888ead2 100644
--- a/akka-testkit/src/test/scala/akka/testkit/DefaultTimeoutSpec.scala
+++ b/akka-testkit/src/test/scala/akka/testkit/DefaultTimeoutSpec.scala
@@ -14,7 +14,7 @@ class DefaultTimeoutSpec extends AnyWordSpec with Matchers with BeforeAndAfterAl
 
   implicit lazy val system: ActorSystem = ActorSystem("AkkaCustomSpec")
 
-  override def afterAll = system.terminate()
+  override def afterAll() = system.terminate()
 
   "A spec with DefaultTimeout" should {
     "use timeout from settings" in {
diff --git a/akka-testkit/src/test/scala/akka/testkit/ImplicitSenderSpec.scala b/akka-testkit/src/test/scala/akka/testkit/ImplicitSenderSpec.scala
index b81721d363..eb16b71ee7 100644
--- a/akka-testkit/src/test/scala/akka/testkit/ImplicitSenderSpec.scala
+++ b/akka-testkit/src/test/scala/akka/testkit/ImplicitSenderSpec.scala
@@ -14,7 +14,7 @@ class ImplicitSenderSpec extends AnyWordSpec with Matchers with BeforeAndAfterAl
 
   implicit lazy val system: ActorSystem = ActorSystem("AkkaCustomSpec")
 
-  override def afterAll = system.terminate()
+  override def afterAll() = system.terminate()
 
   "An ImplicitSender" should {
     "have testActor as its self" in {
diff --git a/project/AkkaDisciplinePlugin.scala b/project/AkkaDisciplinePlugin.scala
index be94261307..7095f4e521 100644
--- a/project/AkkaDisciplinePlugin.scala
+++ b/project/AkkaDisciplinePlugin.scala
@@ -62,7 +62,7 @@ object AkkaDisciplinePlugin extends AutoPlugin {
     "akka-testkit")
 
   lazy val silencerSettings = {
-    val silencerVersion = "1.6.0"
+    val silencerVersion = "1.7.0"
     Seq(
       libraryDependencies ++= Seq(
           compilerPlugin(("com.github.ghik" %% "silencer-plugin" % silencerVersion).cross(CrossVersion.patch)),
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 4cd109154a..b3cc7cb359 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -26,7 +26,7 @@ object Dependencies {
   val logbackVersion = "1.2.3"
 
   val scala212Version = "2.12.11"
-  val scala213Version = "2.13.1"
+  val scala213Version = "2.13.3"
 
   val reactiveStreamsVersion = "1.0.3"