diff --git a/account_statement_base_completion/statement.py b/account_statement_base_completion/statement.py
index dd67e095..95bb350c 100644
--- a/account_statement_base_completion/statement.py
+++ b/account_statement_base_completion/statement.py
@@ -178,7 +178,15 @@ class AccountStatementCompletionRule(orm.Model):
         res = {}
         inv = self._find_invoice(cr, uid, line, inv_type, context=context)
         if inv:
-            res = {'partner_id': inv.partner_id.id,
+            # FIXME use only commercial_partner_id of invoice in 7.1
+            # this is for backward compatibility in 7.0 before 
+            # the refactoring of res.partner
+            if hasattr(inv, 'commercial_partner_id'):
+                partner_id = inv.commercial_partner_id.id
+            else:
+                partner_id = inv.partner_id.id
+
+            res = {'partner_id': partner_id,
                    'account_id': inv.account_id.id,
                    'type': inv_type}
             override_acc = line['master_account_id']