diff --git a/akka-stream-tck/src/test/scala/akka/stream/tck/AkkaPublisherVerification.scala b/akka-stream-tck/src/test/scala/akka/stream/tck/AkkaPublisherVerification.scala
index d2f9f2fa80..6cb4cac268 100644
--- a/akka-stream-tck/src/test/scala/akka/stream/tck/AkkaPublisherVerification.scala
+++ b/akka-stream-tck/src/test/scala/akka/stream/tck/AkkaPublisherVerification.scala
@@ -27,7 +27,8 @@ abstract class AkkaPublisherVerification[T](val env: TestEnvironment, publisherS
 
   def this() = this(false)
 
-  implicit lazy val materializer = ActorFlowMaterializer(ActorFlowMaterializerSettings(system).copy(maxInputBufferSize = 512))(system)
+  implicit lazy val materializer = ActorFlowMaterializer(
+    ActorFlowMaterializerSettings(system).withInputBuffer(initialSize = 512, maxSize = 512))(system)
 
   override def createFailedPublisher(): Publisher[T] =
     TestPublisher.error(new Exception("Unable to serve subscribers right now!"))
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowSpec.scala
index 0f1b05744a..43ab2cbe62 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowSpec.scala
@@ -315,7 +315,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
 
   "A Flow with multiple subscribers (FanOutBox)" must {
     "adapt speed to the currently slowest subscriber" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 1)) {
         val downstream2 = TestSubscriber.manualProbe[Any]()
         publisher.subscribe(downstream2)
@@ -342,7 +342,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "support slow subscriber with fan-out 2" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 2, maximumBufferSize = 2)) {
         val downstream2 = TestSubscriber.manualProbe[Any]()
         publisher.subscribe(downstream2)
@@ -382,7 +382,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "support incoming subscriber while elements were requested before" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 1)) {
         downstreamSubscription.request(5)
         upstream.expectRequest(upstreamSubscription, 1)
@@ -420,7 +420,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "be unblocked when blocking subscriber cancels subscription" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 1)) {
         val downstream2 = TestSubscriber.manualProbe[Any]()
         publisher.subscribe(downstream2)
@@ -457,7 +457,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "call future subscribers' onError after onSubscribe if initial upstream was completed" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 1)) {
         val downstream2 = TestSubscriber.manualProbe[Any]()
         // don't link it just yet
@@ -496,7 +496,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "call future subscribers' onError should be called instead of onSubscribed after initial upstream reported an error" in {
-      new ChainSetup[Int, String](_.map(_ ⇒ throw TestException), settings.copy(initialInputBufferSize = 1),
+      new ChainSetup[Int, String](_.map(_ ⇒ throw TestException), settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 1)) {
         downstreamSubscription.request(1)
         upstreamSubscription.expectRequest(1)
@@ -513,7 +513,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     }
 
     "call future subscribers' onError when all subscriptions were cancelled" in {
-      new ChainSetup(identity, settings.copy(initialInputBufferSize = 1),
+      new ChainSetup(identity, settings.withInputBuffer(initialSize = 1, maxSize = 1),
         toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 16)) {
         upstreamSubscription.expectRequest(1)
         downstreamSubscription.cancel()
@@ -529,7 +529,7 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
 
   "A broken Flow" must {
     "cancel upstream and call onError on current and future downstream subscribers if an internal error occurs" in {
-      new ChainSetup(faultyFlow, settings.copy(initialInputBufferSize = 1), toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 16)) {
+      new ChainSetup(faultyFlow, settings.withInputBuffer(initialSize = 1, maxSize = 1), toFanoutPublisher(initialBufferSize = 1, maximumBufferSize = 16)) {
 
         def checkError(sprobe: TestSubscriber.ManualProbe[Any]): Unit = {
           val error = sprobe.expectError()
diff --git a/akka-stream/src/main/scala/akka/stream/ActorFlowMaterializer.scala b/akka-stream/src/main/scala/akka/stream/ActorFlowMaterializer.scala
index 5c113d9fb8..472c8ebb43 100644
--- a/akka-stream/src/main/scala/akka/stream/ActorFlowMaterializer.scala
+++ b/akka-stream/src/main/scala/akka/stream/ActorFlowMaterializer.scala
@@ -164,6 +164,20 @@ abstract class ActorFlowMaterializer extends FlowMaterializer {
 class MaterializationException(msg: String, cause: Throwable = null) extends RuntimeException(msg, cause)
 
 object ActorFlowMaterializerSettings {
+
+  def apply(
+    initialInputBufferSize: Int,
+    maxInputBufferSize: Int,
+    dispatcher: String,
+    supervisionDecider: Supervision.Decider,
+    subscriptionTimeoutSettings: StreamSubscriptionTimeoutSettings,
+    debugLogging: Boolean,
+    outputBurstLimit: Int,
+    optimizations: Optimizations) =
+    new ActorFlowMaterializerSettings(
+      initialInputBufferSize, maxInputBufferSize, dispatcher, supervisionDecider, subscriptionTimeoutSettings, debugLogging,
+      outputBurstLimit, optimizations)
+
   /**
    * Create [[ActorFlowMaterializerSettings]].
    *
@@ -215,21 +229,34 @@ object ActorFlowMaterializerSettings {
  *
  * This will likely be replaced in the future by auto-tuning these values at runtime.
  */
-final case class ActorFlowMaterializerSettings(
-  initialInputBufferSize: Int,
-  maxInputBufferSize: Int,
-  dispatcher: String,
-  supervisionDecider: Supervision.Decider,
-  subscriptionTimeoutSettings: StreamSubscriptionTimeoutSettings,
-  debugLogging: Boolean,
-  outputBurstLimit: Int,
-  optimizations: Optimizations) {
+final class ActorFlowMaterializerSettings(
+  val initialInputBufferSize: Int,
+  val maxInputBufferSize: Int,
+  val dispatcher: String,
+  val supervisionDecider: Supervision.Decider,
+  val subscriptionTimeoutSettings: StreamSubscriptionTimeoutSettings,
+  val debugLogging: Boolean,
+  val outputBurstLimit: Int,
+  val optimizations: Optimizations) {
 
   require(initialInputBufferSize > 0, "initialInputBufferSize must be > 0")
 
   requirePowerOfTwo(maxInputBufferSize, "maxInputBufferSize")
   require(initialInputBufferSize <= maxInputBufferSize, s"initialInputBufferSize($initialInputBufferSize) must be <= maxInputBufferSize($maxInputBufferSize)")
 
+  private def copy(
+    initialInputBufferSize: Int = this.initialInputBufferSize,
+    maxInputBufferSize: Int = this.maxInputBufferSize,
+    dispatcher: String = this.dispatcher,
+    supervisionDecider: Supervision.Decider = this.supervisionDecider,
+    subscriptionTimeoutSettings: StreamSubscriptionTimeoutSettings = this.subscriptionTimeoutSettings,
+    debugLogging: Boolean = this.debugLogging,
+    outputBurstLimit: Int = this.outputBurstLimit,
+    optimizations: Optimizations = this.optimizations) =
+    new ActorFlowMaterializerSettings(
+      initialInputBufferSize, maxInputBufferSize, dispatcher, supervisionDecider, subscriptionTimeoutSettings, debugLogging,
+      outputBurstLimit, optimizations)
+
   def withInputBuffer(initialSize: Int, maxSize: Int): ActorFlowMaterializerSettings =
     copy(initialInputBufferSize = initialSize, maxInputBufferSize = maxSize)
 
@@ -274,6 +301,9 @@ final case class ActorFlowMaterializerSettings(
 object StreamSubscriptionTimeoutSettings {
   import akka.stream.StreamSubscriptionTimeoutTerminationMode._
 
+  def apply(mode: StreamSubscriptionTimeoutTerminationMode, timeout: FiniteDuration): StreamSubscriptionTimeoutSettings =
+    new StreamSubscriptionTimeoutSettings(mode, timeout)
+
   /** Java API */
   def create(config: Config): StreamSubscriptionTimeoutSettings =
     apply(config)
@@ -289,7 +319,8 @@ object StreamSubscriptionTimeoutSettings {
       timeout = c.getDuration("timeout", TimeUnit.MILLISECONDS).millis)
   }
 }
-final case class StreamSubscriptionTimeoutSettings(mode: StreamSubscriptionTimeoutTerminationMode, timeout: FiniteDuration)
+
+final class StreamSubscriptionTimeoutSettings(val mode: StreamSubscriptionTimeoutTerminationMode, val timeout: FiniteDuration)
 
 sealed abstract class StreamSubscriptionTimeoutTerminationMode