diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 4390c6fc82b..a28122f38cc 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -312,7 +312,7 @@ class MailThread(models.AbstractModel):
             return True
         # discard pending tracking
         self._track_discard()
-        self.env['mail.message'].search([('model', '=', self._name), ('res_id', 'in', self.ids)]).sudo().unlink()
+        self.env['mail.message'].sudo().search([('model', '=', self._name), ('res_id', 'in', self.ids)]).unlink()
         res = super(MailThread, self).unlink()
         self.env['mail.followers'].sudo().search(
             [('res_model', '=', self._name), ('res_id', 'in', self.ids)]
diff --git a/addons/test_mail/tests/test_mail_thread_internals.py b/addons/test_mail/tests/test_mail_thread_internals.py
index 56b9258070a..8a28bfbe37a 100644
--- a/addons/test_mail/tests/test_mail_thread_internals.py
+++ b/addons/test_mail/tests/test_mail_thread_internals.py
@@ -8,7 +8,7 @@ from werkzeug.urls import url_parse, url_decode
 from odoo import exceptions
 from odoo.addons.test_mail.models.test_mail_models import MailTestSimple
 from odoo.addons.test_mail.tests.common import TestMailCommon, TestRecipients
-from odoo.tests.common import tagged, HttpCase
+from odoo.tests.common import tagged, HttpCase, users
 from odoo.tools import mute_logger
 
 
@@ -260,6 +260,23 @@ class TestDiscuss(TestMailCommon, TestRecipients):
         threads_admin = self.test_record.with_user(self.user_admin).search([('message_has_error', '=', True)])
         self.assertEqual(len(threads_admin), 0)
 
+    @users("employee")
+    def test_unlink_notification_message(self):
+        channel = self.env['mail.channel'].create({'name': 'testChannel'})
+        channel.message_notify(
+            body='test',
+            message_type='user_notification',
+            partner_ids=[self.partner_2.id],
+            author_id=2
+        )
+
+        channel_message = self.env['mail.message'].sudo().search([('model', '=', 'mail.channel'), ('res_id', 'in', channel.ids)])
+        self.assertEqual(len(channel_message), 1, "Test message should have been posted")
+
+        channel.unlink()
+        remaining_message = channel_message.exists()
+        self.assertEqual(len(remaining_message), 0, "Test message should have been deleted")
+
 
 @tagged('-at_install', 'post_install')
 class TestMultiCompany(HttpCase):