diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index edd9c34f74..5fd8712f9b 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -195,6 +195,7 @@ class Configuration
                     ->ifTrue(function($v) { return is_array($v) && !empty($v['annotations']) && !empty($v['namespace']); })
                     ->then(function($v){
                         $v['annotations'] = array('namespace' => $v['namespace']);
+                        unset($v['namespace']);
                         return $v;
                     })
                     ->end()