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 055dd4e71d..606ae9337f 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
@@ -454,8 +454,8 @@ class TcpSpec extends AkkaSpec("akka.io.tcp.windows-connection-abort-workaround-
       val binding3F = bind.to(Sink(probe3)).run()
       probe3.expectSubscriptionAndError()
 
-      an[BindFailedException] shouldBe thrownBy { Await.result(binding2F, 1.second) }
-      an[BindFailedException] shouldBe thrownBy { Await.result(binding3F, 1.second) }
+      a[BindFailedException] shouldBe thrownBy { Await.result(binding2F, 1.second) }
+      a[BindFailedException] shouldBe thrownBy { Await.result(binding3F, 1.second) }
 
       // Now unbind first
       Await.result(binding1.unbind(), 1.second)
diff --git a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/GraphJunctionAttributesSpec.scala b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/GraphJunctionAttributesSpec.scala
index cd769bf5c6..267fa95289 100644
--- a/akka-stream-tests/src/test/scala/akka/stream/scaladsl/GraphJunctionAttributesSpec.scala
+++ b/akka-stream-tests/src/test/scala/akka/stream/scaladsl/GraphJunctionAttributesSpec.scala
@@ -28,7 +28,7 @@ class GraphJunctionAttributesSpec extends AkkaSpec {
       val source = Source[(SlowTick, List[FastTick])]() { implicit b ⇒
         import FlowGraph.Implicits._
 
-        val slow = Source(0.seconds, 100.millis, SlowTick)
+        val slow = Source(100.millis, 100.millis, SlowTick)
         val fast = Source(0.seconds, 10.millis, FastTick)
 
         val zip = b add Zip[SlowTick, List[FastTick]]().withAttributes(inputBuffer(1, 1))
@@ -39,10 +39,16 @@ class GraphJunctionAttributesSpec extends AkkaSpec {
         zip.out
       }
 
-      val future = source.grouped(10).runWith(Sink.head)
+      val future = source
+        .drop(1) // account for prefetch
+        .grouped(10)
+        .runWith(Sink.head)
+      val fastTicks = Await.result(future, 2.seconds).map(_._2.size)
 
-      // FIXME #16435 drop(2) needed because first two SlowTicks get only one FastTick
-      Await.result(future, 2.seconds).map(_._2.size).filter(_ == 1).drop(2) should be(Nil)
+      // Account for the possibility for the zip to act as a buffer of two.
+      // If that happens there would be one fast tick for one slow tick in the results.
+      // More explanation in #16435
+      atLeast(8, fastTicks) shouldBe 10 +- 1
     }
   }