diff --git a/jupyterhub/tests/conftest.py b/jupyterhub/tests/conftest.py
index 870bf15e..47482af7 100644
--- a/jupyterhub/tests/conftest.py
+++ b/jupyterhub/tests/conftest.py
@@ -130,7 +130,7 @@ def mockservice_url(request, app):
 @fixture
 def no_patience(app):
     """Set slow-spawning timeouts to zero"""
-    with mock.patch.dict(app.tornado_application.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'slow_spawn_timeout': 0,
                           'slow_stop_timeout': 0}):
         yield
@@ -139,7 +139,7 @@ def no_patience(app):
 @fixture
 def slow_spawn(app):
     """Fixture enabling SlowSpawner"""
-    with mock.patch.dict(app.users.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'spawner_class': mocking.SlowSpawner}):
         yield
 
@@ -147,7 +147,7 @@ def slow_spawn(app):
 @fixture
 def never_spawn(app):
     """Fixture enabling NeverSpawner"""
-    with mock.patch.dict(app.users.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'spawner_class': mocking.NeverSpawner}):
         yield
 
@@ -155,7 +155,7 @@ def never_spawn(app):
 @fixture
 def bad_spawn(app):
     """Fixture enabling BadSpawner"""
-    with mock.patch.dict(app.users.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'spawner_class': mocking.BadSpawner}):
         yield
 
@@ -163,7 +163,7 @@ def bad_spawn(app):
 @fixture
 def slow_bad_spawn(app):
     """Fixture enabling SlowBadSpawner"""
-    with mock.patch.dict(app.users.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'spawner_class': mocking.SlowBadSpawner}):
         yield
 
@@ -171,6 +171,6 @@ def slow_bad_spawn(app):
 @fixture
 def admin_access(app):
     """Grant admin-access with this fixture"""
-    with mock.patch.dict(app.users.settings,
+    with mock.patch.dict(app.tornado_settings,
                          {'admin_access': True}):
         yield
diff --git a/jupyterhub/tests/mocking.py b/jupyterhub/tests/mocking.py
index f819a68e..bce3deec 100644
--- a/jupyterhub/tests/mocking.py
+++ b/jupyterhub/tests/mocking.py
@@ -218,7 +218,7 @@ class MockHub(JupyterHub):
         """Instantiate the tornado Application object"""
         super().init_tornado_application()
         # reconnect tornado_settings so that mocks can update the real thing
-        self.tornado_settings = self.tornado_application.settings
+        self.tornado_settings = self.users.settings = self.tornado_application.settings
 
     @gen.coroutine
     def initialize(self, argv=None):
diff --git a/jupyterhub/tests/test_api.py b/jupyterhub/tests/test_api.py
index 679a5aa4..fd3cd719 100644
--- a/jupyterhub/tests/test_api.py
+++ b/jupyterhub/tests/test_api.py
@@ -518,7 +518,6 @@ def test_never_spawn(app, no_patience, never_spawn):
 
 @mark.gen_test
 def test_bad_spawn(app, no_patience, bad_spawn):
-    settings = app.tornado_application.settings
     db = app.db
     name = 'prim'
     user = add_user(db, app=app, name=name)
@@ -529,7 +528,6 @@ def test_bad_spawn(app, no_patience, bad_spawn):
 
 @mark.gen_test
 def test_slow_bad_spawn(app, no_patience, slow_bad_spawn):
-    settings = app.tornado_application.settings
     db = app.db
     name = 'zaphod'
     user = add_user(db, app=app, name=name)
@@ -545,11 +543,10 @@ def test_slow_bad_spawn(app, no_patience, slow_bad_spawn):
 @mark.gen_test
 def test_spawn_limit(app, no_patience, slow_spawn, request):
     db = app.db
-    settings = app.tornado_application.settings
-    settings['concurrent_spawn_limit'] = 2
-    def _restore_limit():
-        settings['concurrent_spawn_limit'] = 100
-    request.addfinalizer(_restore_limit)
+    p = mock.patch.dict(app.tornado_settings,
+                   {'concurrent_spawn_limit': 2})
+    p.start()
+    request.addfinalizer(p.stop)
 
     # start two pending spawns
     names = ['ykka', 'hjarka']
@@ -597,11 +594,10 @@ def test_spawn_limit(app, no_patience, slow_spawn, request):
 @mark.gen_test
 def test_active_server_limit(app, request):
     db = app.db
-    settings = app.tornado_application.settings
-    settings['active_server_limit'] = 2
-    def _restore_limit():
-        settings['active_server_limit'] = 0
-    request.addfinalizer(_restore_limit)
+    p = mock.patch.dict(app.tornado_settings,
+                   {'active_server_limit': 2})
+    p.start()
+    request.addfinalizer(p.stop)
 
     # start two pending spawns
     names = ['ykka', 'hjarka']
diff --git a/jupyterhub/tests/test_named_servers.py b/jupyterhub/tests/test_named_servers.py
index 55dd470e..ddb025d6 100644
--- a/jupyterhub/tests/test_named_servers.py
+++ b/jupyterhub/tests/test_named_servers.py
@@ -1,4 +1,6 @@
 """Tests for named servers"""
+from unittest import mock
+
 import pytest
 
 from ..utils import url_path_join
@@ -9,12 +11,9 @@ from .utils import async_requests
 
 @pytest.fixture
 def named_servers(app):
-    key = 'allow_named_servers'
-    app.tornado_application.settings[key] = app.tornado_settings[key] = True
-    try:
-        yield True
-    finally:
-        app.tornado_application.settings[key] = app.tornado_settings[key] = False
+    with mock.patch.dict(app.tornado_settings,
+                         {'allow_named_servers': True}):
+        yield
 
 
 @pytest.mark.gen_test
diff --git a/jupyterhub/tests/test_pages.py b/jupyterhub/tests/test_pages.py
index 0155e0e5..fcabdc3f 100644
--- a/jupyterhub/tests/test_pages.py
+++ b/jupyterhub/tests/test_pages.py
@@ -209,7 +209,7 @@ def test_spawn_form(app):
 
 @pytest.mark.gen_test
 def test_spawn_form_admin_access(app, admin_access):
-    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
+    with mock.patch.dict(app.tornado_settings, {'spawner_class': FormSpawner}):
         base_url = ujoin(public_host(app), app.hub.base_url)
         cookies = yield app.login_user('admin')
         u = add_user(app.db, app=app, name='martha')
@@ -232,7 +232,7 @@ def test_spawn_form_admin_access(app, admin_access):
 
 @pytest.mark.gen_test
 def test_spawn_form_with_file(app):
-    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
+    with mock.patch.dict(app.tornado_settings, {'spawner_class': FormSpawner}):
         base_url = ujoin(public_host(app), app.hub.base_url)
         cookies = yield app.login_user('jones')
         orm_u = orm.User.find(app.db, 'jones')
@@ -386,7 +386,7 @@ def test_auto_login(app, request):
     authenticator = Authenticator(auto_login=True)
     authenticator.login_url = lambda base_url: ujoin(base_url, 'dummy')
 
-    with mock.patch.dict(app.tornado_application.settings, {
+    with mock.patch.dict(app.tornado_settings, {
         'authenticator': authenticator,
     }):
         r = yield async_requests.get(base_url)
@@ -397,7 +397,7 @@ def test_auto_login_logout(app):
     name = 'burnham'
     cookies = yield app.login_user(name)
 
-    with mock.patch.dict(app.tornado_application.settings, {
+    with mock.patch.dict(app.tornado_settings, {
         'authenticator': Authenticator(auto_login=True),
     }):
         r = yield async_requests.get(public_host(app) + app.tornado_settings['logout_url'], cookies=cookies)