diff --git a/modules/purchase_trade/lot.py b/modules/purchase_trade/lot.py
index 526417e..c990eb4 100755
--- a/modules/purchase_trade/lot.py
+++ b/modules/purchase_trade/lot.py
@@ -20,7 +20,7 @@ import datetime
 import json
 import logging
 from trytond.exceptions import UserWarning, UserError
-from purchase_trade.service import ContractFactory
+from trytond.modules.purchase_trade.service import ContractFactory
 
 logger = logging.getLogger(__name__)