diff --git a/app/services/notification_service.rb b/app/services/notification_service.rb
index 4af1ab8e4d7f7108a869c87b7175eb0fe77e400b..312b56eb87bee15689de10cdde7a410cbfb8b0fa 100644
--- a/app/services/notification_service.rb
+++ b/app/services/notification_service.rb
@@ -408,7 +408,7 @@ class NotificationService
         [target.author, target.assignee]
       end
 
-    recipients = add_project_watchers(recipients)
+    recipients = add_project_watchers(recipients, project)
     recipients = reject_mention_users(recipients, project)
     recipients = reject_muted_users(recipients, project)