diff --git a/library/Zend/Mvc/Controller/PluginManager.php b/library/Zend/Mvc/Controller/PluginManager.php
index be48e5aeb82..4ca1c28f2be 100644
--- a/library/Zend/Mvc/Controller/PluginManager.php
+++ b/library/Zend/Mvc/Controller/PluginManager.php
@@ -149,7 +149,7 @@ public function validatePlugin($plugin)
     {
         if ($plugin instanceof Plugin\PluginInterface) {
             // we're okay
-            return;
+            return true;
         }
 
         throw new Exception\InvalidPluginException(sprintf(