diff --git a/aleksis/apps/chronos/migrations/0001_initial.py b/aleksis/apps/chronos/migrations/0001_initial.py
index c1842ed902696312eca6b51a1bdbfaf5a71cbc8c..5d6f1b8f87925290f2319a8ac4805b7526504322 100644
--- a/aleksis/apps/chronos/migrations/0001_initial.py
+++ b/aleksis/apps/chronos/migrations/0001_initial.py
@@ -41,6 +41,7 @@ class Migration(migrations.Migration):
                 ),
             ],
             options={
+                "default_permissions": (),
                 "permissions": (
                     ("view_all_timetables", "Can view all timetables"),
                     ("view_timetable_overview", "Can view timetable overview"),
diff --git a/aleksis/apps/chronos/models.py b/aleksis/apps/chronos/models.py
index af432ac7a14cceb80d0f0fa408da3d94e3c60029..a883414aad27e5fe01702561e5d15f1b6da30871 100644
--- a/aleksis/apps/chronos/models.py
+++ b/aleksis/apps/chronos/models.py
@@ -48,7 +48,11 @@ from aleksis.apps.chronos.mixins import (
 from aleksis.apps.chronos.util.date import get_current_year
 from aleksis.apps.chronos.util.format import format_m2m
 from aleksis.core.managers import CurrentSiteManagerWithoutMigrations
-from aleksis.core.mixins import ExtensibleModel, SchoolTermRelatedExtensibleModel
+from aleksis.core.mixins import (
+    ExtensibleModel,
+    GlobalPermissionModel,
+    SchoolTermRelatedExtensibleModel,
+)
 from aleksis.core.models import DashboardWidget, SchoolTerm
 from aleksis.core.util.core_helpers import has_person
 
@@ -1044,7 +1048,7 @@ class ExtraLesson(
         verbose_name_plural = _("Extra lessons")
 
 
-class ChronosGlobalPermissions(ExtensibleModel):
+class ChronosGlobalPermissions(GlobalPermissionModel):
     class Meta:
         managed = False
         permissions = (