diff --git a/modules/purchase_trade/account.py b/modules/purchase_trade/account.py
index e439918..82840db 100644
--- a/modules/purchase_trade/account.py
+++ b/modules/purchase_trade/account.py
@@ -1,5 +1,6 @@
 from trytond.model import ModelSQL, ModelView, fields
 from trytond.pool import PoolMeta
+from trytond.pyson import Eval
 
 __all__ = [
     'PhysicalTradeIFRS',