diff --git a/addons/sale/models/sale_order.py b/addons/sale/models/sale_order.py
index 66bdc9772e4..9f64b5046ad 100644
--- a/addons/sale/models/sale_order.py
+++ b/addons/sale/models/sale_order.py
@@ -415,7 +415,7 @@ class SaleOrder(models.Model):
     @api.depends('partner_id')
     def _compute_user_id(self):
         for order in self:
-            if not order.user_id:
+            if order.partner_id and not order.user_id:
                 order.user_id = order.partner_id.user_id or order.partner_id.commercial_partner_id.user_id or \
                     (self.user_has_groups('sales_team.group_sale_salesman') and self.env.user)