diff --git a/trytond/model/modelstorage.py b/trytond/model/modelstorage.py
index 83480276a9..0b9e243e1e 100644
--- a/trytond/model/modelstorage.py
+++ b/trytond/model/modelstorage.py
@@ -7,6 +7,7 @@ from trytond.model.browse import EvalEnvironment
 import datetime
 import time
 from decimal import Decimal
+import logging
 
 OPERATORS = (
     'child_of',