diff --git a/dev/TestRunner.php b/dev/TestRunner.php
index c85dda21e..fcccbd533 100644
--- a/dev/TestRunner.php
+++ b/dev/TestRunner.php
@@ -265,6 +265,7 @@ HTML;
 	
 	function tearDown() {
 		SapphireTest::kill_temp_db();
+		DB::set_alternative_database_name(null);
 	}
 }