diff --git a/addons/hr/hr_department.py b/addons/hr/hr_department.py
index 0f2c3a908ff..21946469ce4 100644
--- a/addons/hr/hr_department.py
+++ b/addons/hr/hr_department.py
@@ -130,8 +130,8 @@ class res_users(osv.osv):
                 data_dept = obj_dept.read(cr, uid, ids_dept, ['manager_id'], context=context)
                 parent_ids = map(lambda x: x['manager_id'][0], data_dept)
                 cr.execute('SELECT res.user_id FROM hr_employee AS emp JOIN resource_resource AS res ON res.id=emp.resource_id \
-                        WHERE emp.id IN %s', (tuple(parent_ids),))
-                parent_ids = [x[0] for x in cr.fetchall() if x[0]]
+                        WHERE emp.id IN %s AND res.user_id IS NOT NULL', (tuple(parent_ids),))
+                parent_ids = [x[0] for x in cr.fetchall()]
             result[user_id] = parent_ids
         return result