diff --git a/odex25_purchase/odex25_purchase_coc/models/models.py b/odex25_purchase/odex25_purchase_coc/models/models.py
index 22b6f7488..946809555 100644
--- a/odex25_purchase/odex25_purchase_coc/models/models.py
+++ b/odex25_purchase/odex25_purchase_coc/models/models.py
@@ -108,6 +108,8 @@ class AccountInvoiceCustom(models.Model):
     def create(self, vals):
         if 'res_id' in vals:
             del vals['res_id']
+        if 'res_model' in vals:
+            del vals['res_model']
         res = super(AccountInvoiceCustom, self).create(vals)
         return res
 class PurchaseCoC(models.Model):