diff --git a/tests/AliasHandlerTest.php b/tests/AliasHandlerTest.php
index 4e9af1c3..76d3df8a 100644
--- a/tests/AliasHandlerTest.php
+++ b/tests/AliasHandlerTest.php
@@ -11,6 +11,10 @@ class AliasHandlerTest extends \PHPUnit\Framework\TestCase {
 
     public function tearDown() {
         $_SESSION = [];
+        db_query('DELETE FROM alias');
+        db_query('DELETE FROM domain');
+        db_query('DELETE FROM domain_admins');
+
         parent::tearDown();
     }