diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index ea64157fde..a5e36e3f36 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -585,10 +585,7 @@ class Configuration implements ConfigurationInterface
                                     ->ifTrue(function ($v) { return \is_array($v) && isset($v['mime_type']); })
                                     ->then(function ($v) { return $v['mime_type']; })
                                 ->end()
-                                ->beforeNormalization()
-                                    ->ifTrue(function ($v) { return !\is_array($v); })
-                                    ->then(function ($v) { return [$v]; })
-                                ->end()
+                                ->beforeNormalization()->castToArray()->end()
                                 ->prototype('scalar')->end()
                             ->end()
                         ->end()
@@ -646,10 +643,7 @@ class Configuration implements ConfigurationInterface
                     ->fixXmlConfig('loader')
                     ->children()
                         ->arrayNode('loaders')
-                            ->beforeNormalization()
-                                ->ifTrue(function ($v) { return !\is_array($v); })
-                                ->then(function ($v) { return [$v]; })
-                             ->end()
+                            ->beforeNormalization()->castToArray()->end()
                             ->prototype('scalar')->end()
                         ->end()
                     ->end()
@@ -674,10 +668,7 @@ class Configuration implements ConfigurationInterface
                         ->scalarNode('base_path')->defaultValue('')->end()
                         ->arrayNode('base_urls')
                             ->requiresAtLeastOneElement()
-                            ->beforeNormalization()
-                                ->ifTrue(function ($v) { return !\is_array($v); })
-                                ->then(function ($v) { return [$v]; })
-                            ->end()
+                            ->beforeNormalization()->castToArray()->end()
                             ->prototype('scalar')->end()
                         ->end()
                     ->end()
@@ -719,10 +710,7 @@ class Configuration implements ConfigurationInterface
                                     ->scalarNode('base_path')->defaultValue('')->end()
                                     ->arrayNode('base_urls')
                                         ->requiresAtLeastOneElement()
-                                        ->beforeNormalization()
-                                            ->ifTrue(function ($v) { return !\is_array($v); })
-                                            ->then(function ($v) { return [$v]; })
-                                        ->end()
+                                        ->beforeNormalization()->castToArray()->end()
                                         ->prototype('scalar')->end()
                                     ->end()
                                 ->end()
@@ -817,10 +805,7 @@ class Configuration implements ConfigurationInterface
                             ->defaultValue(['loadValidatorMetadata'])
                             ->prototype('scalar')->end()
                             ->treatFalseLike([])
-                            ->validate()
-                                ->ifTrue(function ($v) { return !\is_array($v); })
-                                ->then(function ($v) { return (array) $v; })
-                            ->end()
+                            ->validate()->castToArray()->end()
                         ->end()
                         ->scalarNode('translation_domain')->defaultValue('validators')->end()
                         ->booleanNode('strict_email')->end()