diff --git a/src/server/oasisapi/oidc/keycloak_auth.py b/src/server/oasisapi/oidc/keycloak_auth.py
index 21cdaf3e4..5c98b96a0 100644
--- a/src/server/oasisapi/oidc/keycloak_auth.py
+++ b/src/server/oasisapi/oidc/keycloak_auth.py
@@ -157,7 +157,11 @@ def update_groups(self, user, claims):
         """
         Persist Keycloak groups as local Django groups.
         """
-        keycloak_groups = claims.get('groups', [])
+        keycloak_groups = claims.get('groups', None)
+        if keycloak_groups is None:
+            msg = 'No group found in claim / user_info'
+            raise SuspiciousOperation(msg)
+
         for i, keycloak_group in enumerate(keycloak_groups):
             if keycloak_group.startswith('/'):
                 keycloak_groups[i] = keycloak_group[1:]