diff --git a/addons/account_voucher/voucher.py b/addons/account_voucher/voucher.py
index a1ce08e9dd1..d1dc30c6b67 100755
--- a/addons/account_voucher/voucher.py
+++ b/addons/account_voucher/voucher.py
@@ -251,6 +251,7 @@ class account_voucher(osv.osv):
                 
             date = inv.date
             total_currency = 0
+            acc_id = None
             for i in iml:
                 partner_id=i['partner_id']
                 acc_id = i['account_id']