diff --git a/src/Symfony/Component/HttpKernel/Kernel.php b/src/Symfony/Component/HttpKernel/Kernel.php
index 732a3a7ea8..bf7b82b364 100644
--- a/src/Symfony/Component/HttpKernel/Kernel.php
+++ b/src/Symfony/Component/HttpKernel/Kernel.php
@@ -374,7 +374,7 @@ abstract class Kernel implements KernelInterface
     {
         if (null === $this->rootDir) {
             $r = new \ReflectionObject($this);
-            $this->rootDir = dirname($r->getFileName());
+            $this->rootDir = str_replace('\\', '/', dirname($r->getFileName()));
         }
 
         return $this->rootDir;