diff --git a/addons/sale_service_rating/models/project.py b/addons/sale_service_rating/models/project.py
index f6afa1b4bb9..2db0dcee676 100644
--- a/addons/sale_service_rating/models/project.py
+++ b/addons/sale_service_rating/models/project.py
@@ -8,6 +8,6 @@ class Task(models.Model):
     _inherit = 'project.task'
 
     def rating_get_partner_id(self):
-        if self.partner_id or self.self.order_id.partner_id:
+        if self.partner_id or self.sale_line_id.order_id.partner_id:
             return self.partner_id or self.sale_line_id.order_id.partner_id
         return super(Task, self).rating_get_partner_id()