diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
index 995b1ca9f4eec..f459a63978d38 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -780,7 +780,7 @@ private function registerRouterConfiguration(array $config, ContainerBuilder $co
         $loader->load('routing.xml');
 
         if ($config['utf8']) {
-            $container->getDefinition('routing.loader')->replaceArgument(2, ['utf8' => true]);
+            $container->getDefinition('routing.loader')->replaceArgument(1, ['utf8' => true]);
         }
 
         $container->setParameter('router.resource', $config['resource']);