diff --git a/product/ERP5Security/ERP5UserManager.py b/product/ERP5Security/ERP5UserManager.py
index 0e7eb81aa52f6cfe38c1d99e52f945400679810f..d622ea80ca314d7cffc289adc72ba06bf1f1e40f 100755
--- a/product/ERP5Security/ERP5UserManager.py
+++ b/product/ERP5Security/ERP5UserManager.py
@@ -102,7 +102,8 @@ class ERP5UserManager(BasePlugin):
                 t_id = (t_id,)
                             
             if t_id:
-                person_module = self.person
+                person_module = self.getPortalObject()\
+                                        .getDefaultModule('Person')
                 for user_name in t_id:
                     user = getattr(person_module, user_name, None)
                     if user: