diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
index 5b64b4e524..caed2c2916 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php
@@ -309,7 +309,7 @@ abstract class FrameworkExtensionTest extends TestCase
 
     protected function createContainerFromFile($file, $data = array())
     {
-        $cacheKey = md5($file.serialize($data));
+        $cacheKey = md5(get_class($this).$file.serialize($data));
         if (isset(self::$containerCache[$cacheKey])) {
             return self::$containerCache[$cacheKey];
         }