diff --git a/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php b/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
index efd99784e4..8e5247faea 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
@@ -152,7 +152,7 @@ trait MicroKernelTrait
     {
         $file = (new \ReflectionObject($this))->getFileName();
         /* @var RoutingPhpFileLoader $kernelLoader */
-        $kernelLoader = $loader->getResolver()->resolve($file);
+        $kernelLoader = $loader->getResolver()->resolve($file, 'php');
         $kernelLoader->setCurrentDir(\dirname($file));
         $collection = new RouteCollection();