diff --git a/ext/3rd-party-addons/sale_partner_incoterm/models/sale_order.py b/ext/3rd-party-addons/sale_partner_incoterm/models/sale_order.py
index 40fbc352..f4e668c1 100644
--- a/ext/3rd-party-addons/sale_partner_incoterm/models/sale_order.py
+++ b/ext/3rd-party-addons/sale_partner_incoterm/models/sale_order.py
@@ -28,5 +28,5 @@ class SaleOrder(models.Model):
     def onchange_partner_id(self):
         res = super(SaleOrder, self).onchange_partner_id()
         if self.partner_id:
-            res['value']['incoterm'] = self.env['res.partner'].browse(self.partner_id).sale_incoterm_id.id
+            self.update({'incoterm': self.env['res.partner'].browse(self.partner_id.id).sale_incoterm_id.id})
         return res