diff --git a/carrier.py b/carrier.py
index a67420936b..4814bce090 100644
--- a/carrier.py
+++ b/carrier.py
@@ -4,26 +4,11 @@ import copy
 from decimal import Decimal
 
 from trytond.model import Model, ModelSQL, ModelView, fields
-from trytond.pyson import Eval, Bool, PYSON
+from trytond.pyson import Eval, Bool, Id
 from trytond.pool import Pool
 from trytond.transaction import Transaction
 
 
-class Id(PYSON):
-
-    def __init__(self, module, fs_id):
-        super(Id, self).__init__()
-        self._module = module
-        self._fs_id = fs_id
-
-    def pyson(self):
-        model_data_obj = Pool().get('ir.model.data')
-        return model_data_obj.get_id(self._module, self._fs_id)
-
-    def types(self):
-        return set([int])
-
-
 class Carrier(Model):
     _name = 'carrier'