diff --git a/addons/project/models/project.py b/addons/project/models/project.py
index 2f334db50e6..d4eb770440a 100644
--- a/addons/project/models/project.py
+++ b/addons/project/models/project.py
@@ -886,7 +886,7 @@ class Task(models.Model):
     @api.multi
     def _notify_get_reply_to(self, default=None, records=None, company=None, doc_names=None):
         """ Override to set alias of tasks to their project if any. """
-        aliases = self.mapped('project_id')._notify_get_reply_to(default=default, records=None, company=company, doc_names=None)
+        aliases = self.sudo().mapped('project_id')._notify_get_reply_to(default=default, records=None, company=company, doc_names=None)
         res = {task.id: aliases.get(task.project_id.id) for task in self}
         leftover = self.filtered(lambda rec: not rec.project_id)
         if leftover: