diff --git a/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php b/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
index f81a1c740a..92e92c0fef 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php
@@ -35,6 +35,7 @@ abstract class KernelTestCase extends TestCase
     private function doTearDown()
     {
         static::ensureKernelShutdown();
+        static::$kernel = null;
     }
 
     /**