diff --git a/addons/project/models/project_task.py b/addons/project/models/project_task.py
index 4a8b9d12a1e..9af5933e743 100644
--- a/addons/project/models/project_task.py
+++ b/addons/project/models/project_task.py
@@ -897,7 +897,7 @@ class Task(models.Model):
                 vals['date_assign'] = fields.Datetime.now()
                 if not project_id:
                     user_ids = self._fields['user_ids'].convert_to_cache(vals.get('user_ids', []), self)
-                    if self.env.user.id not in user_ids:
+                    if self.env.user.id not in list(user_ids) + [SUPERUSER_ID]:
                         vals['user_ids'] = [Command.set(list(user_ids) + [self.env.user.id])]
             # Stage change: Update date_end if folded stage and date_last_stage_update
             if vals.get('stage_id'):