diff --git a/axes/tests/settings.py b/axes/tests/settings.py
index <HASH>..<HASH> 100644
--- a/axes/tests/settings.py
+++ b/axes/tests/settings.py
@@ -72,3 +72,5 @@ USE_TZ = False
 LOGIN_REDIRECT_URL = "/admin/"
 
 AXES_FAILURE_LIMIT = 10
+
+DEFAULT_AUTO_FIELD = "django.db.models.AutoField"
Add DEFAULT_AUTO_FIELD to test settings.