diff --git a/aleksis/apps/chronos/managers.py b/aleksis/apps/chronos/managers.py
index e1fc4aaae92648099f4bf73e7d36ac2f73072a5c..7093cfec2c698370f6178eb9efbcd8b3d852018f 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):
@@ -39,7 +40,7 @@ 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 5d0d9285dfe3470622e4488fdf1f475999e96e76..382a3e34c36c611ee6cf0b0ab4e4f8876b56181f 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
@@ -386,7 +387,7 @@ class AbsenceReason(ExtensibleModel):
 
 
 class Absence(ExtensibleModel):
-    objects = models.Manager.from_queryset(AbsenceQuerySet)()
+    objects = CurrentSiteManager.from_queryset(AbsenceQuerySet)()
 
     reason = models.ForeignKey(
         "AbsenceReason",
@@ -489,7 +490,7 @@ 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)
@@ -601,7 +602,7 @@ class Break(ExtensibleModel):
 
 
 class Supervision(ExtensibleModel):
-    objects = models.Manager.from_queryset(SupervisionQuerySet)()
+    objects = CurrentSiteManager.from_queryset(SupervisionQuerySet)()
 
     area = models.ForeignKey(
         SupervisionArea,
@@ -669,7 +670,7 @@ 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)
 
@@ -724,7 +725,7 @@ 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(