Fix model class

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 = (