diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index d96705d1ff..855bf6f81f 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -217,8 +217,8 @@ class Configuration implements ConfigurationInterface
                             ->fixXmlConfig('resource')
                             ->children()
                                 ->arrayNode('resources')
-                                    ->defaultValue(array('FrameworkBundle:Form'))
-                                    ->prototype('scalar')->end()
+                                    ->addDefaultChildrenWhenNoneSet()
+                                    ->prototype('scalar')->defaultValue('FrameworkBundle:Form')->end()
                                     ->validate()
                                         ->ifTrue(function($v) {return !in_array('FrameworkBundle:Form', $v); })
                                         ->then(function($v){
diff --git a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
index 4e5fe7ce6b..9829fad629 100644
--- a/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/TwigBundle/DependencyInjection/Configuration.php
@@ -54,8 +54,8 @@ class Configuration implements ConfigurationInterface
                     ->fixXmlConfig('resource')
                     ->children()
                         ->arrayNode('resources')
-                            ->defaultValue(array('form_div_layout.html.twig'))
-                            ->prototype('scalar')->end()
+                            ->addDefaultChildrenWhenNoneSet()
+                            ->prototype('scalar')->defaultValue('form_div_layout.html.twig')->end()
                             ->setExample(array('MyBundle::form.html.twig'))
                             ->validate()
                                 ->ifTrue(function($v) { return !in_array('form_div_layout.html.twig', $v); })