diff --git a/wagtail/admin/tests/tests.py b/wagtail/admin/tests/tests.py
index 7951791ac2..ffe3d08636 100644
--- a/wagtail/admin/tests/tests.py
+++ b/wagtail/admin/tests/tests.py
@@ -331,17 +331,38 @@ class TestUserHasAnyPagePermission(TestCase, WagtailTestUtils):
 
 
 class Test404(TestCase, WagtailTestUtils):
-    def test_admin_404_template_used(self):
+    def test_admin_404_template_used_append_slash_true(self):
         self.login()
-        response = self.client.get('/admin/sdfgdsfgdsfgsdf')
-        self.assertEqual(response.status_code, 404)
-        self.assertTemplateUsed(response, 'wagtailadmin/404.html')
+        with self.settings(APPEND_SLASH=True):
+            response = self.client.get('/admin/sdfgdsfgdsfgsdf', follow=True)
+
+            # Check 404 error after CommonMiddleware redirect
+            self.assertEqual(response.status_code, 404)
+            self.assertTemplateUsed(response, 'wagtailadmin/404.html')
 
     def test_not_logged_in_redirect(self):
-        response = self.client.get('/admin/sdfgdsfgdsfgsdf')
+        response = self.client.get('/admin/sdfgdsfgdsfgsdf/')
 
         # Check that the user was redirected to the login page and that next was set correctly
-        self.assertRedirects(response, reverse('wagtailadmin_login') + '?next=/admin/sdfgdsfgdsfgsdf')
+        self.assertRedirects(response, reverse('wagtailadmin_login') + '?next=/admin/sdfgdsfgdsfgsdf/')
+
+
+class TestAdminURLAppendSlash(TestCase, WagtailTestUtils):
+    def setUp(self):
+        # Find root page
+        self.root_page = Page.objects.get(id=2)
+
+    def test_return_correct_view_for_correct_url_without_ending_slash(self):
+        self.login()
+        with self.settings(APPEND_SLASH=True):
+            # Remove trailing slash from URL
+            response = self.client.get(reverse('wagtailadmin_explore_root')[:-1], follow=True)
+
+            # Check that correct page is returned after CommonMiddleware redirect
+            self.assertEqual(response.status_code, 200)
+            self.assertTemplateUsed(response, 'wagtailadmin/pages/index.html')
+            self.assertEqual(Page.objects.get(id=1), response.context['parent_page'])
+            self.assertTrue(response.context['pages'].paginator.object_list.filter(id=self.root_page.id).exists())
 
 
 class TestRemoveStaleContentTypes(TestCase):
diff --git a/wagtail/admin/urls/__init__.py b/wagtail/admin/urls/__init__.py
index 703d8cf20c..f97b09125f 100644
--- a/wagtail/admin/urls/__init__.py
+++ b/wagtail/admin/urls/__init__.py
@@ -93,13 +93,26 @@ urlpatterns += [
 
     # Password reset
     path('password_reset/', include(wagtailadmin_password_reset_urls)),
-
-    # Default view (will show 404 page)
-    # This must be the last URL in this file!
-    re_path(r'^', home.default),
 ]
 
 
+# Default view (will show 404 page)
+# This must be the last URL in this file!
+
+if settings.APPEND_SLASH:
+    # Only catch unrecognized patterns with a trailing slash
+    # and let CommonMiddleware handle adding a slash to every other pattern
+    urlpatterns += [
+        re_path(r'^.*/$', home.default),
+    ]
+
+else:
+    # Catch all unrecognized patterns
+    urlpatterns += [
+        re_path(r'^', home.default),
+    ]
+
+
 # Hook in our own 404 handler
 def display_custom_404(view_func):
     @functools.wraps(view_func)