diff --git a/addons/website_event_track/models/event.py b/addons/website_event_track/models/event.py
index d289f908619..eacbed2ebb4 100644
--- a/addons/website_event_track/models/event.py
+++ b/addons/website_event_track/models/event.py
@@ -130,8 +130,8 @@ class event_event(models.Model):
     def _get_tracks_tag_ids(self):
         self.tracks_tag_ids = self.track_ids.mapped('tag_ids').ids
 
-    track_ids = fields.One2many('event.track', 'event_id', 'Tracks', copy=True)
-    sponsor_ids = fields.One2many('event.sponsor', 'event_id', 'Sponsors', copy=True)
+    track_ids = fields.One2many('event.track', 'event_id', 'Tracks')
+    sponsor_ids = fields.One2many('event.sponsor', 'event_id', 'Sponsors')
     blog_id = fields.Many2one('blog.blog', 'Event Blog')
     show_track_proposal = fields.Boolean('Talks Proposals')
     show_tracks = fields.Boolean('Multiple Tracks')