diff --git a/test/test_gc.py b/test/test_gc.py
index 27c44c61c..02d14bfb4 100644
--- a/test/test_gc.py
+++ b/test/test_gc.py
@@ -10,17 +10,22 @@ PUBLIC_USER = 'public'
 REPO = 'somerepo'
 
 class TestGarbageColection(unittest.TestCase):
-  def setUp(self):
-    self._old_tm_expiration = app.config['TIME_MACHINE_DELTA_SECONDS']
-    app.config['TIME_MACHINE_DELTA_SECONDS'] = 0
+  @staticmethod
+  def _set_tag_expiration_policy(namespace, expiration_s):
+    namespace_user = model.get_user(namespace)
+    model.change_user_tag_expiration(namespace_user, expiration_s)
 
+  def setUp(self):
     setup_database_for_testing(self)
+
+    self._set_tag_expiration_policy(ADMIN_ACCESS_USER, 0)
+    self._set_tag_expiration_policy(PUBLIC_USER, 0)
+
     self.app = app.test_client()
     self.ctx = app.test_request_context()
     self.ctx.__enter__()
 
   def tearDown(self):
-    app.config['TIME_MACHINE_DELTA_SECONDS'] = self._old_tm_expiration
     finished_database_for_testing(self)
     self.ctx.__exit__(True, None, None)