diff --git a/netbox/netbox/monkey.py b/netbox/netbox/monkey.py
index 6a8f515df8e..be256e3ae60 100644
--- a/netbox/netbox/monkey.py
+++ b/netbox/netbox/monkey.py
@@ -22,7 +22,7 @@ def get_unique_validators(field_name, model_field):
     # START custom logic
     conditions = {
         cond for cond in conditions
-        if cond.referenced_base_fields == field_set
+        if cond is None or cond.referenced_base_fields == field_set
     }
     # END custom logic