diff --git a/aleksis/apps/chronos/managers.py b/aleksis/apps/chronos/managers.py
index e6ef49cd8a02bf04c4ea0f34380533b67d801235..c54fa63a32d048aab0eac88cb4edee283b5c36ae 100644
--- a/aleksis/apps/chronos/managers.py
+++ b/aleksis/apps/chronos/managers.py
@@ -2,6 +2,7 @@ from datetime import date, datetime, timedelta
 from enum import Enum
 from typing import Optional, Union
 
+from django.contrib.sites.managers import CurrentSiteManager
 from django.db import models
 from django.db.models import Count, F, Q
 
@@ -26,7 +27,7 @@ class TimetableType(Enum):
         return cls.__members__.get(s.upper())
 
 
-class LessonPeriodManager(models.Manager):
+class LessonPeriodManager(CurrentSiteManager):
     """Manager adding specific methods to lesson periods."""
 
     def get_queryset(self):
@@ -40,7 +41,7 @@ class LessonPeriodManager(models.Manager):
         )
 
 
-class LessonSubstitutionManager(models.Manager):
+class LessonSubstitutionManager(CurrentSiteManager):
     """Manager adding specific methods to lesson substitutions."""
 
     def get_queryset(self):
diff --git a/aleksis/apps/chronos/models.py b/aleksis/apps/chronos/models.py
index 6d7c302747459514e1d3b955b75294da4e049915..58bb7d855bfdcc1f602b1bdd050cf5a9b1c4a86e 100644
--- a/aleksis/apps/chronos/models.py
+++ b/aleksis/apps/chronos/models.py
@@ -3,6 +3,7 @@ from __future__ import annotations
 from datetime import date, datetime, time, timedelta
 from typing import Dict, Optional, Tuple, Union
 
+from django.contrib.sites.managers import CurrentSiteManager
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import Max, Min, Q
@@ -388,7 +389,7 @@ class AbsenceReason(ExtensibleModel):
 
 
 class Absence(ExtensibleModel):
-    objects = models.Manager.from_queryset(AbsenceQuerySet)()
+    objects = CurrentSiteManager.from_queryset(AbsenceQuerySet)()
 
     reason = models.ForeignKey(
         "AbsenceReason",
@@ -491,7 +492,7 @@ class Exam(ExtensibleModel):
 
 
 class Holiday(ExtensibleModel):
-    objects = models.Manager.from_queryset(HolidayQuerySet)()
+    objects = CurrentSiteManager.from_queryset(HolidayQuerySet)()
 
     title = models.CharField(verbose_name=_("Title"), max_length=255)
     date_start = models.DateField(verbose_name=_("Start date"), null=True)
@@ -603,7 +604,7 @@ class Break(ExtensibleModel):
 
 
 class Supervision(ExtensibleModel):
-    objects = models.Manager.from_queryset(SupervisionQuerySet)()
+    objects = CurrentSiteManager.from_queryset(SupervisionQuerySet)()
 
     area = models.ForeignKey(
         SupervisionArea,
@@ -671,7 +672,7 @@ class SupervisionSubstitution(ExtensibleModel):
 class Event(ExtensibleModel, GroupPropertiesMixin, TeacherPropertiesMixin):
     label_ = "event"
 
-    objects = models.Manager.from_queryset(EventQuerySet)()
+    objects = CurrentSiteManager.from_queryset(EventQuerySet)()
 
     title = models.CharField(verbose_name=_("Title"), max_length=255, blank=True)
 
@@ -726,7 +727,7 @@ class Event(ExtensibleModel, GroupPropertiesMixin, TeacherPropertiesMixin):
 class ExtraLesson(ExtensibleModel, GroupPropertiesMixin):
     label_ = "extra_lesson"
 
-    objects = models.Manager.from_queryset(ExtraLessonQuerySet)()
+    objects = CurrentSiteManager.from_queryset(ExtraLessonQuerySet)()
 
     week = models.IntegerField(verbose_name=_("Week"), default=CalendarWeek.current_week)
     period = models.ForeignKey(