diff --git a/addons/calendar/models/calendar_attendee.py b/addons/calendar/models/calendar_attendee.py
index f5fc83591dcab..8f2babee6d6aa 100644
--- a/addons/calendar/models/calendar_attendee.py
+++ b/addons/calendar/models/calendar_attendee.py
@@ -118,6 +118,8 @@ def _send_mail_to_attendees(self, mail_template, force_send=False):
                     attachment_values += [
                         (0, 0, {'name': 'invitation.ics',
                                 'mimetype': 'text/calendar',
+                                'res_id': event_id,
+                                'res_model': 'calendar.event',
                                 'datas': base64.b64encode(ics_file)})
                     ]
                 body = mail_template._render_field(
diff --git a/addons/calendar/tests/test_calendar.py b/addons/calendar/tests/test_calendar.py
index d3351215f0445..e64b0fb823eff 100644
--- a/addons/calendar/tests/test_calendar.py
+++ b/addons/calendar/tests/test_calendar.py
@@ -6,7 +6,7 @@
 
 from odoo import fields, Command
 from odoo.addons.base.tests.common import HttpCaseWithUserDemo
-from odoo.tests import Form, HttpCase, tagged
+from odoo.tests import Form, tagged, new_test_user
 from odoo.addons.base.tests.common import SavepointCaseWithUserDemo
 import pytz
 import re
@@ -351,6 +351,23 @@ def _test_emails_has_attachment(self, partners):
         # no more email should be sent
         _test_one_mail_per_attendee(self, partners)
 
+    def test_event_creation_internal_user_invitation_ics(self):
+        """ Check that internal user can read invitation.ics attachment """
+        internal_user = new_test_user(self.env, login='internal_user', groups='base.group_user')
+
+        partner = internal_user.partner_id
+        self.event_tech_presentation.write({
+            'partner_ids': [(4, partner.id)],
+        })
+        msg = self.env['mail.message'].search([
+            ('notified_partner_ids', 'in', partner.id),
+        ])
+        msg.invalidate_recordset()
+
+
+        # internal user can read the attachment without errors
+        self.assertEqual(msg.with_user(internal_user).attachment_ids.name, 'invitation.ics')
+
     def test_event_creation_sudo_other_company(self):
         """ Check Access right issue when create event with sudo