diff --git a/evennia/contrib/tests.py b/evennia/contrib/tests.py
index c94f85039..c576de29f 100644
--- a/evennia/contrib/tests.py
+++ b/evennia/contrib/tests.py
@@ -222,6 +222,8 @@ class ForceUTCDatetime(datetime.datetime):
 
 
 @patch('evennia.contrib.extended_room.datetime.datetime', ForceUTCDatetime)
+# mock gametime to return April 9, 2064, at 21:06 (spring evening)
+@patch('evennia.utils.gametime.gametime', new=Mock(return_value=2975000766))
 class TestExtendedRoom(CommandTest):
     room_typeclass = extended_room.ExtendedRoom
     DETAIL_DESC = "A test detail."
@@ -236,8 +238,6 @@ class TestExtendedRoom(CommandTest):
         self.room1.db.details = {'testdetail': self.DETAIL_DESC}
         self.room1.db.spring_desc = self.SPRING_DESC
         self.room1.db.desc = self.OLD_DESC
-        # mock gametime to return April 9, 2064, at 21:06 (spring evening)
-        gametime.gametime = Mock(return_value=2975000766)
 
     def test_return_appearance(self):
         # get the appearance of a non-extended room for contrast purposes
@@ -607,11 +607,8 @@ def _testcallback():
     pass
 
 
+@patch('evennia.utils.gametime.gametime', new=Mock(return_value=2975000898.46))
 class TestCustomGameTime(EvenniaTest):
-    def setUp(self):
-        super().setUp()
-        gametime.gametime = Mock(return_value=2975000898.46)  # does not seem to work
-
     def tearDown(self):
         if hasattr(self, "timescript"):
             self.timescript.stop()
diff --git a/evennia/utils/tests/test_gametime.py b/evennia/utils/tests/test_gametime.py
index a2c005f17..032513c7e 100644
--- a/evennia/utils/tests/test_gametime.py
+++ b/evennia/utils/tests/test_gametime.py
@@ -5,6 +5,7 @@ Unit tests for the utilities of the evennia.utils.gametime module.
 import time
 from unittest.mock import Mock
 
+from django.conf import settings
 from django.test import TestCase
 
 from evennia.utils import gametime
@@ -13,12 +14,18 @@ time.time = Mock(return_value=1555595378.0)
 
 
 class TestGametime(TestCase):
-    def setUp(self):
+    def setUp(self) -> None:
         gametime.SERVER_RUNTIME = 600.0
         gametime.SERVER_START_TIME = time.time() - 300
         gametime.SERVER_RUNTIME_LAST_UPDATED = time.time() - 30
         gametime.TIMEFACTOR = 5.0
 
+    def tearDown(self) -> None:
+        gametime.SERVER_RUNTIME_LAST_UPDATED = 0.0
+        gametime.SERVER_RUNTIME = 0.0
+        gametime.SERVER_START_TIME = 0.0
+        gametime.TIMEFACTOR = settings.TIME_FACTOR
+
     def test_runtime(self):
         self.assertAlmostEqual(gametime.runtime(), 630.0)
 
@@ -69,6 +76,7 @@ class TestGametime(TestCase):
         self.assertIsInstance(script, gametime.TimeScript)
         self.assertAlmostEqual(script.interval, 17280)
         self.assertEqual(script.repeats, 1)
+        script.stop()
 
     def test_repeat_schedule(self):
         callback = Mock()
@@ -76,3 +84,4 @@ class TestGametime(TestCase):
         self.assertIsInstance(script, gametime.TimeScript)
         self.assertAlmostEqual(script.interval, 12)
         self.assertEqual(script.repeats, -1)
+        script.stop()