diff --git a/party.py b/party.py
index 0ca5767..913ca5c 100644
--- a/party.py
+++ b/party.py
@@ -3,13 +3,12 @@
 from trytond.model import fields
 from trytond.pool import PoolMeta
 
-__metaclass__ = PoolMeta
-
 __all__ = ['Party']
 
 
 class Party:
     __name__ = 'party.party'
+    __metaclass__ = PoolMeta
 
     customer_to_invoice = fields.Property(
             fields.Many2One('party.party', 'Customer to invoice'))