diff --git a/src/Symfony/Component/Form/FormConfigInterface.php b/src/Symfony/Component/Form/FormConfigInterface.php
index e66570cf5f..b7083544a4 100644
--- a/src/Symfony/Component/Form/FormConfigInterface.php
+++ b/src/Symfony/Component/Form/FormConfigInterface.php
@@ -99,7 +99,7 @@ interface FormConfigInterface
     /**
      * Returns the data mapper of the form.
      *
-     * @return DataMapperInterface The data mapper
+     * @return DataMapperInterface|null The data mapper
      */
     public function getDataMapper();