diff --git a/hijack_admin/tests/test_checks.py b/hijack_admin/tests/test_checks.py
index <HASH>..<HASH> 100644
--- a/hijack_admin/tests/test_checks.py
+++ b/hijack_admin/tests/test_checks.py
@@ -77,6 +77,7 @@ else:
             class CustomAdminSite(admin.AdminSite):
                 pass
 
+            _default_site = admin.site
             admin.site = CustomAdminSite()
             admin.autodiscover()
 
@@ -86,3 +87,4 @@ else:
             self.assertFalse(warnings)
 
             admin.site.unregister(get_user_model())
+            admin.site = _default_site
Put back admin.site to default at the end of the test