diff --git a/Tests/ImmutableEventDispatcherTest.php b/Tests/ImmutableEventDispatcherTest.php
index be91f65..9aaaec6 100644
--- a/Tests/ImmutableEventDispatcherTest.php
+++ b/Tests/ImmutableEventDispatcherTest.php
@@ -24,7 +24,7 @@
 class ImmutableEventDispatcherTest extends TestCase
 {
     /**
-     * @var MockObject
+     * @var MockObject&EventDispatcherInterface
      */
     private $innerDispatcher;