diff --git a/akka-stream/src/main/scala/akka/stream/javadsl/Flow.scala b/akka-stream/src/main/scala/akka/stream/javadsl/Flow.scala
index 6f6c1388e4..9cf078863f 100755
--- a/akka-stream/src/main/scala/akka/stream/javadsl/Flow.scala
+++ b/akka-stream/src/main/scala/akka/stream/javadsl/Flow.scala
@@ -2476,8 +2476,8 @@ final class Flow[In, Out, Mat](delegate: scaladsl.Flow[In, Out, Mat]) extends Gr
    *
    * '''Cancels when''' downstream cancels
    */
-  def zipWithIndex: Flow[In, Pair[Out, Long], Mat] =
-    new Flow(delegate.zipWithIndex.map { case (elem, index) ⇒ Pair(elem, index) })
+  def zipWithIndex: Flow[In, Pair[Out, java.lang.Long], Mat] =
+    new Flow(delegate.zipWithIndex.map { case (elem, index) ⇒ Pair[Out, java.lang.Long](elem, index) })
 
   /**
    * If the first element has not passed through this stage before the provided timeout, the stream is failed
diff --git a/akka-stream/src/main/scala/akka/stream/javadsl/Source.scala b/akka-stream/src/main/scala/akka/stream/javadsl/Source.scala
index a3047c66ff..d970740aaf 100755
--- a/akka-stream/src/main/scala/akka/stream/javadsl/Source.scala
+++ b/akka-stream/src/main/scala/akka/stream/javadsl/Source.scala
@@ -1042,8 +1042,8 @@ final class Source[Out, Mat](delegate: scaladsl.Source[Out, Mat]) extends Graph[
    *
    * '''Cancels when''' downstream cancels
    */
-  def zipWithIndex: javadsl.Source[Pair[Out @uncheckedVariance, Long], Mat] =
-    new Source(delegate.zipWithIndex.map { case (elem, index) ⇒ Pair(elem, index) })
+  def zipWithIndex: javadsl.Source[Pair[Out @uncheckedVariance, java.lang.Long], Mat] =
+    new Source(delegate.zipWithIndex.map { case (elem, index) ⇒ Pair[Out, java.lang.Long](elem, index) })
 
   /**
    * Shortcut for running this `Source` with a foreach procedure. The given procedure is invoked
diff --git a/akka-stream/src/main/scala/akka/stream/javadsl/SubFlow.scala b/akka-stream/src/main/scala/akka/stream/javadsl/SubFlow.scala
index 3ed1ca5da9..dca9ac243a 100755
--- a/akka-stream/src/main/scala/akka/stream/javadsl/SubFlow.scala
+++ b/akka-stream/src/main/scala/akka/stream/javadsl/SubFlow.scala
@@ -1518,8 +1518,8 @@ class SubFlow[In, Out, Mat](delegate: scaladsl.SubFlow[Out, Mat, scaladsl.Flow[I
    *
    * '''Cancels when''' downstream cancels
    */
-  def zipWithIndex: SubFlow[In, akka.japi.Pair[Out @uncheckedVariance, Long], Mat] =
-    new SubFlow(delegate.zipWithIndex.map { case (elem, index) ⇒ akka.japi.Pair(elem, index) })
+  def zipWithIndex: SubFlow[In, akka.japi.Pair[Out @uncheckedVariance, java.lang.Long], Mat] =
+    new SubFlow(delegate.zipWithIndex.map { case (elem, index) ⇒ akka.japi.Pair[Out, java.lang.Long](elem, index) })
 
   /**
    * If the first element has not passed through this stage before the provided timeout, the stream is failed