diff --git a/tests/admin_custom_urls/models.py b/tests/admin_custom_urls/models.py
index 51725d42536..5a1b2f5c2e2 100644
--- a/tests/admin_custom_urls/models.py
+++ b/tests/admin_custom_urls/models.py
@@ -77,6 +77,7 @@ class CarAdmin(admin.ModelAdmin):
             request, obj, post_url_continue=reverse('admin:admin_custom_urls_car_history', args=[obj.pk]))
 
 
-admin.site.register(Action, ActionAdmin)
-admin.site.register(Person, PersonAdmin)
-admin.site.register(Car, CarAdmin)
+site = admin.AdminSite(name='admin_custom_urls')
+site.register(Action, ActionAdmin)
+site.register(Person, PersonAdmin)
+site.register(Car, CarAdmin)
diff --git a/tests/admin_custom_urls/tests.py b/tests/admin_custom_urls/tests.py
index 8177a144bb4..2255ff59dcf 100644
--- a/tests/admin_custom_urls/tests.py
+++ b/tests/admin_custom_urls/tests.py
@@ -50,7 +50,7 @@ class AdminCustomUrlsTest(TestCase):
         """
         Ensure GET on the add_view works.
         """
-        add_url = reverse('admin:admin_custom_urls_action_add')
+        add_url = reverse('admin_custom_urls:admin_custom_urls_action_add')
         self.assertTrue(add_url.endswith('/!add/'))
         response = self.client.get(add_url)
         self.assertIsInstance(response, TemplateResponse)
@@ -61,7 +61,7 @@ class AdminCustomUrlsTest(TestCase):
         Ensure GET on the add_view plus specifying a field value in the query
         string works.
         """
-        response = self.client.get(reverse('admin:admin_custom_urls_action_add'), {'name': 'My Action'})
+        response = self.client.get(reverse('admin_custom_urls:admin_custom_urls_action_add'), {'name': 'My Action'})
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, 'value="My Action"')
 
@@ -74,7 +74,7 @@ class AdminCustomUrlsTest(TestCase):
             "name": 'Action added through a popup',
             "description": "Description of added action",
         }
-        response = self.client.post(reverse('admin:admin_custom_urls_action_add'), post_data)
+        response = self.client.post(reverse('admin_custom_urls:admin_custom_urls_action_add'), post_data)
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, 'dismissAddRelatedObjectPopup')
         self.assertContains(response, 'Action added through a popup')
@@ -85,7 +85,7 @@ class AdminCustomUrlsTest(TestCase):
         """
         # Should get the change_view for model instance with PK 'add', not show
         # the add_view
-        url = reverse('admin:%s_action_change' % Action._meta.app_label,
+        url = reverse('admin_custom_urls:%s_action_change' % Action._meta.app_label,
                 args=(quote('add'),))
         response = self.client.get(url)
         self.assertEqual(response.status_code, 200)
@@ -93,7 +93,7 @@ class AdminCustomUrlsTest(TestCase):
 
         # Should correctly get the change_view for the model instance with the
         # funny-looking PK (the one with a 'path/to/html/document.html' value)
-        url = reverse('admin:%s_action_change' % Action._meta.app_label,
+        url = reverse('admin_custom_urls:%s_action_change' % Action._meta.app_label,
                 args=(quote("path/to/html/document.html"),))
         response = self.client.get(url)
         self.assertEqual(response.status_code, 200)
@@ -110,11 +110,11 @@ class AdminCustomUrlsTest(TestCase):
         post_data = {'name': 'John Doe'}
         self.assertEqual(Person.objects.count(), 0)
         response = self.client.post(
-            reverse('admin:admin_custom_urls_person_add'), post_data)
+            reverse('admin_custom_urls:admin_custom_urls_person_add'), post_data)
         persons = Person.objects.all()
         self.assertEqual(len(persons), 1)
         self.assertRedirects(
-            response, reverse('admin:admin_custom_urls_person_history', args=[persons[0].pk]))
+            response, reverse('admin_custom_urls:admin_custom_urls_person_history', args=[persons[0].pk]))
 
     def test_post_save_change_redirect(self):
         """
@@ -128,9 +128,9 @@ class AdminCustomUrlsTest(TestCase):
         person = Person.objects.all()[0]
         post_data = {'name': 'Jack Doe'}
         response = self.client.post(
-            reverse('admin:admin_custom_urls_person_change', args=[person.pk]), post_data)
+            reverse('admin_custom_urls:admin_custom_urls_person_change', args=[person.pk]), post_data)
         self.assertRedirects(
-            response, reverse('admin:admin_custom_urls_person_delete', args=[person.pk]))
+            response, reverse('admin_custom_urls:admin_custom_urls_person_delete', args=[person.pk]))
 
     def test_post_url_continue(self):
         """
@@ -140,8 +140,8 @@ class AdminCustomUrlsTest(TestCase):
         post_data = {'name': 'SuperFast', '_continue': '1'}
         self.assertEqual(Car.objects.count(), 0)
         response = self.client.post(
-            reverse('admin:admin_custom_urls_car_add'), post_data)
+            reverse('admin_custom_urls:admin_custom_urls_car_add'), post_data)
         cars = Car.objects.all()
         self.assertEqual(len(cars), 1)
         self.assertRedirects(
-            response, reverse('admin:admin_custom_urls_car_history', args=[cars[0].pk]))
+            response, reverse('admin_custom_urls:admin_custom_urls_car_history', args=[cars[0].pk]))
diff --git a/tests/admin_custom_urls/urls.py b/tests/admin_custom_urls/urls.py
index eb91d283d45..103f9b0121a 100644
--- a/tests/admin_custom_urls/urls.py
+++ b/tests/admin_custom_urls/urls.py
@@ -1,6 +1,7 @@
 from django.conf.urls import include, url
-from django.contrib import admin
+
+from .models import site
 
 urlpatterns = [
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', include(site.urls)),
 ]
diff --git a/tests/gis_tests/geoadmin/models.py b/tests/gis_tests/geoadmin/models.py
index cf8470e792c..9769558f48b 100644
--- a/tests/gis_tests/geoadmin/models.py
+++ b/tests/gis_tests/geoadmin/models.py
@@ -16,4 +16,5 @@ class City(models.Model):
     def __str__(self):
         return self.name
 
-admin.site.register(City, admin.OSMGeoAdmin)
+site = admin.AdminSite(name='admin_gis')
+site.register(City, admin.OSMGeoAdmin)
diff --git a/tests/gis_tests/geoadmin/tests.py b/tests/gis_tests/geoadmin/tests.py
index 86c8ce9a1ae..07af5a0d647 100644
--- a/tests/gis_tests/geoadmin/tests.py
+++ b/tests/gis_tests/geoadmin/tests.py
@@ -8,7 +8,7 @@ if HAS_GEOS:
     from django.contrib.gis.geos import Point
 
     from .admin import UnmodifiableAdmin
-    from .models import City
+    from .models import site, City
 
 
 @skipUnlessDBFeature("gis_enabled")
@@ -16,14 +16,14 @@ if HAS_GEOS:
 class GeoAdminTest(TestCase):
 
     def test_ensure_geographic_media(self):
-        geoadmin = admin.site._registry[City]
+        geoadmin = site._registry[City]
         admin_js = geoadmin.media.render_js()
         self.assertTrue(any(geoadmin.openlayers_url in js for js in admin_js))
 
     def test_olmap_OSM_rendering(self):
         delete_all_btn = """<a href="javascript:geodjango_point.clearFeatures()">Delete all Features</a>"""
 
-        original_geoadmin = admin.site._registry[City]
+        original_geoadmin = site._registry[City]
         params = original_geoadmin.get_map_widget(City._meta.get_field('point')).params
         result = original_geoadmin.get_map_widget(City._meta.get_field('point'))(
         ).render('point', Point(-79.460734, 40.18476), params)
@@ -33,21 +33,21 @@ class GeoAdminTest(TestCase):
 
         self.assertIn(delete_all_btn, result)
 
-        admin.site.unregister(City)
-        admin.site.register(City, UnmodifiableAdmin)
+        site.unregister(City)
+        site.register(City, UnmodifiableAdmin)
         try:
-            geoadmin = admin.site._registry[City]
+            geoadmin = site._registry[City]
             params = geoadmin.get_map_widget(City._meta.get_field('point')).params
             result = geoadmin.get_map_widget(City._meta.get_field('point'))(
             ).render('point', Point(-79.460734, 40.18476), params)
 
             self.assertNotIn(delete_all_btn, result)
         finally:
-            admin.site.unregister(City)
-            admin.site.register(City, original_geoadmin.__class__)
+            site.unregister(City)
+            site.register(City, original_geoadmin.__class__)
 
     def test_olmap_WMS_rendering(self):
-        geoadmin = admin.GeoModelAdmin(City, admin.site)
+        geoadmin = admin.GeoModelAdmin(City, site)
         result = geoadmin.get_map_widget(City._meta.get_field('point'))(
         ).render('point', Point(-79.460734, 40.18476))
         self.assertIn(
@@ -59,7 +59,7 @@ class GeoAdminTest(TestCase):
         """
         Check that changes are accurately noticed by OpenLayersWidget.
         """
-        geoadmin = admin.site._registry[City]
+        geoadmin = site._registry[City]
         form = geoadmin.get_changelist_form(None)()
         has_changed = form.fields['point'].has_changed
 
diff --git a/tests/proxy_models/admin.py b/tests/proxy_models/admin.py
index 72556c34a50..ba67f7829f9 100644
--- a/tests/proxy_models/admin.py
+++ b/tests/proxy_models/admin.py
@@ -2,5 +2,6 @@ from django.contrib import admin
 
 from .models import ProxyTrackerUser, TrackerUser
 
-admin.site.register(TrackerUser)
-admin.site.register(ProxyTrackerUser)
+site = admin.AdminSite(name='admin_proxy')
+site.register(TrackerUser)
+site.register(ProxyTrackerUser)
diff --git a/tests/proxy_models/tests.py b/tests/proxy_models/tests.py
index 1aea80902e8..98244327a30 100644
--- a/tests/proxy_models/tests.py
+++ b/tests/proxy_models/tests.py
@@ -433,17 +433,17 @@ class ProxyModelAdminTests(TestCase):
         proxy = ProxyTrackerUser.objects.get(name='Django Pony')
 
         user_str = 'Tracker user: <a href="%s">%s</a>' % (
-            reverse('admin:proxy_models_trackeruser_change', args=(user.pk,)), user
+            reverse('admin_proxy:proxy_models_trackeruser_change', args=(user.pk,)), user
         )
         proxy_str = 'Proxy tracker user: <a href="%s">%s</a>' % (
-            reverse('admin:proxy_models_proxytrackeruser_change', args=(proxy.pk,)), proxy
+            reverse('admin_proxy:proxy_models_proxytrackeruser_change', args=(proxy.pk,)), proxy
         )
 
         self.client.login(username='super', password='secret')
-        response = self.client.get(reverse('admin:proxy_models_trackeruser_delete', args=(user.pk,)))
+        response = self.client.get(reverse('admin_proxy:proxy_models_trackeruser_delete', args=(user.pk,)))
         delete_str = response.context['deleted_objects'][0]
         self.assertEqual(delete_str, user_str)
-        response = self.client.get(reverse('admin:proxy_models_proxytrackeruser_delete', args=(proxy.pk,)))
+        response = self.client.get(reverse('admin_proxy:proxy_models_proxytrackeruser_delete', args=(proxy.pk,)))
         delete_str = response.context['deleted_objects'][0]
         self.assertEqual(delete_str, proxy_str)
         self.client.logout()
diff --git a/tests/proxy_models/urls.py b/tests/proxy_models/urls.py
index eb91d283d45..854ac780403 100644
--- a/tests/proxy_models/urls.py
+++ b/tests/proxy_models/urls.py
@@ -1,6 +1,7 @@
 from django.conf.urls import include, url
-from django.contrib import admin
+
+from .admin import site
 
 urlpatterns = [
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', include(site.urls)),
 ]
diff --git a/tests/timezones/admin.py b/tests/timezones/admin.py
index bd6c4e10c87..a650e110cc7 100644
--- a/tests/timezones/admin.py
+++ b/tests/timezones/admin.py
@@ -6,10 +6,10 @@ from .models import Event, Timestamp
 class EventAdmin(admin.ModelAdmin):
     list_display = ('dt',)
 
-admin.site.register(Event, EventAdmin)
-
 
 class TimestampAdmin(admin.ModelAdmin):
     readonly_fields = ('created', 'updated')
 
-admin.site.register(Timestamp, TimestampAdmin)
+site = admin.AdminSite(name='admin_tz')
+site.register(Event, EventAdmin)
+site.register(Timestamp, TimestampAdmin)
diff --git a/tests/timezones/tests.py b/tests/timezones/tests.py
index d87e2d25665..8c1d5331655 100644
--- a/tests/timezones/tests.py
+++ b/tests/timezones/tests.py
@@ -1100,26 +1100,26 @@ class AdminTests(TestCase):
     @requires_tz_support
     def test_changelist(self):
         e = Event.objects.create(dt=datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC))
-        response = self.client.get(reverse('admin:timezones_event_changelist'))
+        response = self.client.get(reverse('admin_tz:timezones_event_changelist'))
         self.assertContains(response, e.dt.astimezone(EAT).isoformat())
 
     def test_changelist_in_other_timezone(self):
         e = Event.objects.create(dt=datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC))
         with timezone.override(ICT):
-            response = self.client.get(reverse('admin:timezones_event_changelist'))
+            response = self.client.get(reverse('admin_tz:timezones_event_changelist'))
         self.assertContains(response, e.dt.astimezone(ICT).isoformat())
 
     @requires_tz_support
     def test_change_editable(self):
         e = Event.objects.create(dt=datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC))
-        response = self.client.get(reverse('admin:timezones_event_change', args=(e.pk,)))
+        response = self.client.get(reverse('admin_tz:timezones_event_change', args=(e.pk,)))
         self.assertContains(response, e.dt.astimezone(EAT).date().isoformat())
         self.assertContains(response, e.dt.astimezone(EAT).time().isoformat())
 
     def test_change_editable_in_other_timezone(self):
         e = Event.objects.create(dt=datetime.datetime(2011, 9, 1, 10, 20, 30, tzinfo=UTC))
         with timezone.override(ICT):
-            response = self.client.get(reverse('admin:timezones_event_change', args=(e.pk,)))
+            response = self.client.get(reverse('admin_tz:timezones_event_change', args=(e.pk,)))
         self.assertContains(response, e.dt.astimezone(ICT).date().isoformat())
         self.assertContains(response, e.dt.astimezone(ICT).time().isoformat())
 
@@ -1128,7 +1128,7 @@ class AdminTests(TestCase):
         Timestamp.objects.create()
         # re-fetch the object for backends that lose microseconds (MySQL)
         t = Timestamp.objects.get()
-        response = self.client.get(reverse('admin:timezones_timestamp_change', args=(t.pk,)))
+        response = self.client.get(reverse('admin_tz:timezones_timestamp_change', args=(t.pk,)))
         self.assertContains(response, t.created.astimezone(EAT).isoformat())
 
     def test_change_readonly_in_other_timezone(self):
@@ -1136,5 +1136,5 @@ class AdminTests(TestCase):
         # re-fetch the object for backends that lose microseconds (MySQL)
         t = Timestamp.objects.get()
         with timezone.override(ICT):
-            response = self.client.get(reverse('admin:timezones_timestamp_change', args=(t.pk,)))
+            response = self.client.get(reverse('admin_tz:timezones_timestamp_change', args=(t.pk,)))
         self.assertContains(response, t.created.astimezone(ICT).isoformat())
diff --git a/tests/timezones/urls.py b/tests/timezones/urls.py
index 1d1ec38f643..e5c88a0025a 100644
--- a/tests/timezones/urls.py
+++ b/tests/timezones/urls.py
@@ -1,8 +1,7 @@
 from django.conf.urls import include, url
-from django.contrib import admin
 
 from . import admin as tz_admin  # NOQA: register tz_admin
 
 urlpatterns = [
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', include(tz_admin.site.urls)),
 ]