foo.diff

diff --git a/tests/contenttypes_tests/tests.py b/tests/contenttypes_tests/tests.py
index 2d86dfa..9e5eaf5 100644
--- a/tests/contenttypes_tests/tests.py
+++ b/tests/contenttypes_tests/tests.py
@@ -7,12 +7,10 @@ from django.contrib.contenttypes.fields import (
 )
 from django.contrib.contenttypes.models import ContentType
 from django.core import checks
-from django.db import models, router, connections
-from django.db.utils import ConnectionRouter
+from django.db import connections, models, router
 from django.test import TestCase
 from django.test.utils import override_settings
 from django.utils.encoding import force_str
-from django.utils.functional import cached_property
 
 from .models import Author, Article, SchemeIncludedURL
 
@@ -339,7 +337,7 @@ class GenericRelationshipTests(IsolatedModelsTestCase):
         self.assertEqual(errors, expected)
 
 
-class MasterSlaveRouter(object):
+class TestRouter(object):
     def db_for_read(self, model, **hints):
         return 'other'
 
@@ -350,26 +348,6 @@ class MasterSlaveRouter(object):
 class ContentTypesMultidbTestCase(TestCase):
 
     def setUp(self):
-        """
-        We need to override the database routers; this is not possible with
-        override_settings, because they are cached. The cache is not supposed
-        to be overriden, hence the slightly complicated hack.
-        """
-        self.orig_routers = router._routers
-        router._routers = ['contenttypes_tests.tests.MasterSlaveRouter']
-        cached_property(ConnectionRouter.routers.func).__get__(router)
-
-    def tearDown(self):
-        router._routers = self.orig_routers
-        cached_property(ConnectionRouter.routers.func).__get__(router)
-
-    def test_multidb(self):
-        """
-        Test that, when using multiple databases, we use the db_for_read (see
-        #20401).
-        """
-        ContentType.objects.clear_cache()
-
         # Whenever a test starts executing, only the "default" database is
         # connected. We explicitly connect to the "other" database here. If we
         # don't do it, then it will be implicitly connected further below when
@@ -379,6 +357,18 @@ class ContentTypesMultidbTestCase(TestCase):
         # assertNumQueries().
         connections['other'].ensure_connection()
 
-        with self.assertNumQueries(0, using='default'), \
-                self.assertNumQueries(1, using='other'):
-            ContentType.objects.get_for_model(Author)
+        self.old_routers = router.routers
+        router.routers = [TestRouter()]
+
+    def tearDown(self):
+        router.routers = self.old_routers
+
+    def test_multidb(self):
+        """
+        Test that, when using multiple databases, we use the db_for_read (see
+        #20401).
+        """
+        ContentType.objects.clear_cache()
+        with self.assertNumQueries(0, using='default'):
+            with self.assertNumQueries(1, using='other'):
+                ContentType.objects.get_for_model(Author)