diff --git a/src/Symfony/Component/DependencyInjection/Extension/Extension.php b/src/Symfony/Component/DependencyInjection/Extension/Extension.php
index e5c51a7b58..b821ea68db 100644
--- a/src/Symfony/Component/DependencyInjection/Extension/Extension.php
+++ b/src/Symfony/Component/DependencyInjection/Extension/Extension.php
@@ -75,11 +75,11 @@ abstract class Extension implements ExtensionInterface, ConfigurationExtensionIn
         return Container::underscore($classBaseName);
     }
 
-    final protected function processConfiguration(ConfigurationInterface $configuration, array $configs)
+    final protected function processConfiguration(ConfigurationInterface $configuration, array $configs, $normalizeKeys = true)
     {
         $processor = new Processor();
 
-        return $processor->processConfiguration($configuration, $configs);
+        return $processor->processConfiguration($configuration, $configs, $normalizeKeys);
     }
 
     /**