diff --git a/lib/test/Symfony1ProjectTestCase.php b/lib/test/Symfony1ProjectTestCase.php
index 4bde0c3e9..2300a74b3 100644
--- a/lib/test/Symfony1ProjectTestCase.php
+++ b/lib/test/Symfony1ProjectTestCase.php
@@ -19,6 +19,7 @@ class Symfony1ProjectTestCase extends TestCase
 {
     public function resetSfConfig()
     {
+        sfConfig::clear();
         sfConfig::set('sf_symfony_lib_dir', realpath(__DIR__.'/../lib'));
         sfConfig::set('sf_test_cache_dir', sys_get_temp_dir().'/sf_test_project');
     }