diff --git a/addons/website_event/controllers/main.py b/addons/website_event/controllers/main.py
index 48b6b19936c..f0c5351801f 100644
--- a/addons/website_event/controllers/main.py
+++ b/addons/website_event/controllers/main.py
@@ -332,15 +332,14 @@ class WebsiteEventController(http.Controller):
         return list(registrations.values())
 
     def _create_attendees_from_registration_post(self, event, registration_data):
-        attendees_sudo = request.env['event.registration'].sudo()
-
+        registrations_to_create = []
         for registration_values in registration_data:
             registration_values['event_id'] = event.id
             if not registration_values.get('partner_id'):
                 registration_values['partner_id'] = request.env.user.partner_id.id
-            attendees_sudo += request.env['event.registration'].sudo().create(registration_values)
+            registrations_to_create.append(registration_values)
 
-        return attendees_sudo
+        return request.env['event.registration'].sudo().create(registrations_to_create)
 
     @http.route(['''/event/<model("event.event"):event>/registration/confirm'''], type='http', auth="public", methods=['POST'], website=True)
     def registration_confirm(self, event, **post):
diff --git a/addons/website_event_sale/controllers/main.py b/addons/website_event_sale/controllers/main.py
index d9a84510319..00ca7cfd51c 100644
--- a/addons/website_event_sale/controllers/main.py
+++ b/addons/website_event_sale/controllers/main.py
@@ -29,17 +29,13 @@ class WebsiteEventSaleController(WebsiteEventController):
         if any(info.get('event_ticket_id') for info in registration_data):
             order = request.website.sale_get_order(force_create=1)
 
-        order_attendee_ids = set()
         for info in [r for r in registration_data if r.get('event_ticket_id')]:
             ticket = request.env['event.event.ticket'].sudo().browse(info['event_ticket_id'])
-            cart_values = order.with_context(event_ticket_id=ticket.id, fixed_price=True)._cart_update(product_id=ticket.product_id.id, add_qty=1, registration_data=[info])
-            order_attendee_ids |= set(cart_values.get('attendee_ids', []))
+            cart_values = order.with_context(event_ticket_id=ticket.id, fixed_price=True)._cart_update(product_id=ticket.product_id.id, add_qty=1)
+            info['sale_order_id'] = order.id
+            info['sale_order_line_id'] = cart_values.get('line_id')
 
-        attendees_sudo = super(WebsiteEventSaleController, self)._create_attendees_from_registration_post(event, [r for r in registration_data if not r['event_ticket_id']])
-        if order_attendee_ids:
-            attendees_sudo |= request.env['event.registration'].sudo().browse(order_attendee_ids)
-
-        return attendees_sudo
+        return super(WebsiteEventSaleController, self)._create_attendees_from_registration_post(event, registration_data)
 
     @http.route()
     def registration_confirm(self, event, **post):
diff --git a/addons/website_event_sale/models/sale_order.py b/addons/website_event_sale/models/sale_order.py
index 3a7c1c9f307..d092b751366 100644
--- a/addons/website_event_sale/models/sale_order.py
+++ b/addons/website_event_sale/models/sale_order.py
@@ -91,10 +91,8 @@ class SaleOrder(models.Model):
             attendees.action_cancel()
         # adding attendees
         elif ticket and new_qty > old_qty:
-            line = OrderLine.browse(values['line_id'])
-            line._update_registrations(confirm=False, cancel_to_draft=True, registration_data=kwargs.get('registration_data', []))
-            # add in return values the registrations, to display them on website (or not)
-            values['attendee_ids'] = self.env['event.registration'].search([('sale_order_line_id', '=', line.id), ('state', '!=', 'cancel')]).ids
+            # do not do anything, attendees will be created at SO confirmation if not given previously
+            pass
         return values