diff --git a/php/tests/php_implementation_test.php b/php/tests/php_implementation_test.php
index 307b749..db3c361 100644
--- a/php/tests/php_implementation_test.php
+++ b/php/tests/php_implementation_test.php
@@ -538,7 +538,7 @@
 
     /**
      * @expectedException Exception
-     * @expectedExceptionMessage Expect Foo\TestMessage_Sub.
+     * @expectedExceptionMessage Expect Foo\TestMessage\Sub.
      */
     public function testArraysForMessagesThrowsException()
     {