diff --git a/akka-testkit/src/test/scala/akka/testkit/TestActorRefSpec.scala b/akka-testkit/src/test/scala/akka/testkit/TestActorRefSpec.scala
index f95b78d028..47c4908148 100644
--- a/akka-testkit/src/test/scala/akka/testkit/TestActorRefSpec.scala
+++ b/akka-testkit/src/test/scala/akka/testkit/TestActorRefSpec.scala
@@ -235,6 +235,7 @@ class TestActorRefSpec extends WordSpec with MustMatchers with BeforeAndAfterEac
       val ref = TestActorRef[WorkerActor].start()
       ref.isDefinedAt("work") must be (true)
       ref.isDefinedAt("sleep") must be (false)
+      intercept[IllegalActorStateException] { ref("work") }
       val ch = Future.channel()
       ref ! ch
       val f = ch.future