diff --git a/addons/account_voucher/account_voucher.py b/addons/account_voucher/account_voucher.py
index 423026251c2..f97f3f6af3c 100644
--- a/addons/account_voucher/account_voucher.py
+++ b/addons/account_voucher/account_voucher.py
@@ -1070,7 +1070,8 @@ class account_voucher(osv.osv):
             if line.amount == line.amount_unreconciled:
                 if not line.move_line_id.amount_residual:
                     raise osv.except_osv(_('Wrong bank statement line'),_("You have to delete the bank statement line which the payment was reconciled to manually. Please check the payment of the partner %s by the amount of %s.")%(line.voucher_id.partner_id.name, line.voucher_id.amount))
-                currency_rate_difference = line.move_line_id.amount_residual - amount
+                sign = voucher_brw.type in ('payment', 'purchase') and -1 or 1
+                currency_rate_difference = sign * (line.move_line_id.amount_residual - amount)
             else:
                 currency_rate_difference = 0.0
             move_line = {