diff --git a/addons/mail/models/res_users.py b/addons/mail/models/res_users.py
index d0c16736ef8..ee3ee5f6b1c 100644
--- a/addons/mail/models/res_users.py
+++ b/addons/mail/models/res_users.py
@@ -27,11 +27,11 @@ class Users(models.Model):
         """
         init_res = super(Users, self).__init__(pool, cr)
         # duplicate list to avoid modifying the original reference
-        self.SELF_WRITEABLE_FIELDS = list(self.SELF_WRITEABLE_FIELDS)
-        self.SELF_WRITEABLE_FIELDS.extend(['notify_email'])
+        type(self).SELF_WRITEABLE_FIELDS = list(self.SELF_WRITEABLE_FIELDS)
+        type(self).SELF_WRITEABLE_FIELDS.extend(['notify_email'])
         # duplicate list to avoid modifying the original reference
-        self.SELF_READABLE_FIELDS = list(self.SELF_READABLE_FIELDS)
-        self.SELF_READABLE_FIELDS.extend(['notify_email', 'alias_domain', 'alias_name'])
+        type(self).SELF_READABLE_FIELDS = list(self.SELF_READABLE_FIELDS)
+        type(self).SELF_READABLE_FIELDS.extend(['notify_email', 'alias_domain', 'alias_name'])
         return init_res
 
     def get_alias_model_name(self, vals):
diff --git a/addons/website_forum/models/res_users.py b/addons/website_forum/models/res_users.py
index 44206d2b27e..3a5d8c92395 100644
--- a/addons/website_forum/models/res_users.py
+++ b/addons/website_forum/models/res_users.py
@@ -12,7 +12,7 @@ class Users(models.Model):
 
     def __init__(self, pool, cr):
         init_res = super(Users, self).__init__(pool, cr)
-        self.SELF_WRITEABLE_FIELDS = list(
+        type(self).SELF_WRITEABLE_FIELDS = list(
             set(
                 self.SELF_WRITEABLE_FIELDS +
                 ['country_id', 'city', 'website', 'website_description', 'website_published']))