diff --git a/website_event_attendee_signup/models/event_registration.py b/website_event_attendee_signup/models/event_registration.py
index 8fcbd37..318cabf 100644
--- a/website_event_attendee_signup/models/event_registration.py
+++ b/website_event_attendee_signup/models/event_registration.py
@@ -26,6 +26,9 @@ def _update_attendee_partner_id(self, vals):
             return vals
 
         login = attendee_partner.email
+        if not login:
+            return vals
+
         user = Users.search([("login", "=ilike", login)])
         if user:
             # already has user with given address