diff --git a/src/Composer/Config/ConfigSourceInterface.php b/src/Composer/Config/ConfigSourceInterface.php
index 030123cc4..42bac5623 100644
--- a/src/Composer/Config/ConfigSourceInterface.php
+++ b/src/Composer/Config/ConfigSourceInterface.php
@@ -26,7 +26,7 @@ interface ConfigSourceInterface
      * @param string      $name   Name
      * @param array|false $config Configuration
      */
-    public function addRepository($name, $config/* , $append = true */);
+    public function addRepository($name, $config, $append = true);
 
     /**
      * Remove a repository