diff --git a/akka-stream/src/main/scala/akka/stream/impl/fusing/GraphInterpreter.scala b/akka-stream/src/main/scala/akka/stream/impl/fusing/GraphInterpreter.scala
index b8e32a957f..6dae4b87c5 100644
--- a/akka-stream/src/main/scala/akka/stream/impl/fusing/GraphInterpreter.scala
+++ b/akka-stream/src/main/scala/akka/stream/impl/fusing/GraphInterpreter.scala
@@ -248,12 +248,6 @@ private[stream] object GraphInterpreter {
   private[stream] def currentInterpreterOrNull: GraphInterpreter =
     _currentInterpreter.get()(0).asInstanceOf[GraphInterpreter]
 
-  /**
-   * INTERNAL API
-   */
-  private[stream] def setCurrentInterpreter(gi: GraphInterpreter) =
-    _currentInterpreter.get()(0) = gi
-
 }
 
 /**
@@ -502,8 +496,9 @@ private[stream] final class GraphInterpreter(
    */
   def execute(eventLimit: Int): Unit = {
     if (Debug) println(s"$Name ---------------- EXECUTE (running=$runningStages, shutdown=${shutdownCounter.mkString(",")})")
-    val previousInterpreter = currentInterpreterOrNull
-    setCurrentInterpreter(this)
+    val currentInterpreterHolder = _currentInterpreter.get()
+    val previousInterpreter = currentInterpreterHolder(0)
+    currentInterpreterHolder(0) = this
     try {
       var eventsRemaining = eventLimit
       while (eventsRemaining > 0 && queueTail != queueHead) {
@@ -518,7 +513,7 @@ private[stream] final class GraphInterpreter(
         eventsRemaining -= 1
       }
     } finally {
-      setCurrentInterpreter(previousInterpreter)
+      currentInterpreterHolder(0) = previousInterpreter
     }
     if (Debug) println(s"$Name ---------------- $queueStatus (running=$runningStages, shutdown=${shutdownCounter.mkString(",")})")
     // TODO: deadlock detection