diff --git a/modules/purchase_trade/valuation.py b/modules/purchase_trade/valuation.py
index a37fa1b..42d26c8 100644
--- a/modules/purchase_trade/valuation.py
+++ b/modules/purchase_trade/valuation.py
@@ -10,7 +10,7 @@ from sql.aggregate import Count, Max, Min, Sum, Avg, BoolOr
 from sql.conditionals import Case
 from sql import Column, Literal
 from sql.functions import CurrentTimestamp, DateTrunc
-from trytond.wizard import Button, StateTransition, StateView, Wizard
+from trytond.wizard import Button, StateAction, StateTransition, StateView, Wizard
 from itertools import chain, groupby
 from operator import itemgetter
 import datetime