diff --git a/akka-stream-testkit/src/main/resources/reference.conf b/akka-stream-testkit/src/main/resources/reference.conf
new file mode 100644
index 0000000000..7a99c683ad
--- /dev/null
+++ b/akka-stream-testkit/src/main/resources/reference.conf
@@ -0,0 +1,3 @@
+akka.stream.testkit {
+  all-stages-stopped-timeout = 5 s
+}
diff --git a/akka-stream-testkit/src/main/scala/akka/stream/testkit/scaladsl/StreamTestKit.scala b/akka-stream-testkit/src/main/scala/akka/stream/testkit/scaladsl/StreamTestKit.scala
index 17912fc335..8092aef841 100644
--- a/akka-stream-testkit/src/main/scala/akka/stream/testkit/scaladsl/StreamTestKit.scala
+++ b/akka-stream-testkit/src/main/scala/akka/stream/testkit/scaladsl/StreamTestKit.scala
@@ -4,6 +4,8 @@
 
 package akka.stream.testkit.scaladsl
 
+import java.util.concurrent.TimeUnit.MILLISECONDS
+
 import akka.actor.{ ActorRef, ActorSystem }
 import akka.annotation.InternalApi
 import akka.stream._
@@ -43,7 +45,9 @@ object StreamTestKit {
   /** INTERNAL API */
   @InternalApi private[testkit] def assertNoChildren(sys: ActorSystem, supervisor: ActorRef): Unit = {
     val probe = TestProbe()(sys)
-    probe.within(5.seconds) {
+    val c = sys.settings.config.getConfig("akka.stream.testkit")
+    val timeout = c.getDuration("all-stages-stopped-timeout", MILLISECONDS).millis
+    probe.within(timeout) {
       try probe.awaitAssert {
         supervisor.tell(StreamSupervisor.GetChildren, probe.ref)
         val children = probe.expectMsgType[StreamSupervisor.Children].children