diff --git a/stages/admin.py b/stages/admin.py
index 0df6bd1..d84d436 100644
--- a/stages/admin.py
+++ b/stages/admin.py
@@ -5,7 +5,6 @@ import zipfile
 from django import forms
 from django.contrib import admin
 from django.db import models
-from django.db.models import Case, Count, When
 from django.http import HttpResponse
 from django.urls import reverse
 from django.utils.html import format_html
@@ -63,9 +62,7 @@ class ArchivedListFilter(admin.BooleanFieldListFilter):
 class KlassRelatedListFilter(admin.RelatedFieldListFilter):
     def field_choices(self, field, request, model_admin):
         return [
-            (k.pk, k.name) for k in Klass.objects.annotate(
-                num_students=Count(Case(When(student__archived=False, then=1)))
-            ).filter(num_students__gt=0).order_by('name')
+            (k.pk, k.name) for k in Klass.active.order_by('name')
         ]
 
 
diff --git a/stages/models.py b/stages/models.py
index 294ee14..abd6a38 100644
--- a/stages/models.py
+++ b/stages/models.py
@@ -4,6 +4,7 @@ from datetime import date, timedelta
 
 from django.conf import settings
 from django.db import models
+from django.db.models import Case, Count, When
 
 from . import utils
 
@@ -47,6 +48,13 @@ class Level(models.Model):
             return None
 
 
+class ActiveKlassManager(models.Manager):
+    def get_queryset(self):
+        return super().get_queryset().annotate(
+            num_students=Count(Case(When(student__archived=False, then=1)))
+        ).filter(num_students__gt=0)
+
+
 class Klass(models.Model):
     name = models.CharField(max_length=10, verbose_name='Nom', unique=True)
     section = models.ForeignKey(Section, verbose_name='Filière', on_delete=models.PROTECT)
@@ -54,6 +62,9 @@ class Klass(models.Model):
     teacher = models.ForeignKey('Teacher', blank=True, null=True,
         on_delete=models.SET_NULL, verbose_name='Maître de classe')
 
+    objects = models.Manager()
+    active = ActiveKlassManager()
+
     class Meta:
         verbose_name = "Classe"
 
diff --git a/stages/views.py b/stages/views.py
index 14cde77..58516a2 100644
--- a/stages/views.py
+++ b/stages/views.py
@@ -15,7 +15,7 @@ from django.contrib import messages
 from django.core.files import File
 from django.core.mail import EmailMessage
 from django.db import transaction
-from django.db.models import Case, Count, Value, When, Q, Sum
+from django.db.models import Count, Value, Q, Sum
 from django.db.models.functions import Concat
 from django.http import HttpResponse, HttpResponseNotAllowed, HttpResponseRedirect
 from django.shortcuts import get_object_or_404, redirect
@@ -83,8 +83,7 @@ class CorporationView(DetailView):
 
 
 class KlassListView(ListView):
-    queryset = Klass.objects.all().annotate(num_students=Count(Case(When(student__archived=False, then=1)))
-                                 ).filter(num_students__gt=0).order_by('section', 'name')
+    queryset = Klass.active.order_by('section', 'name')
     template_name = 'classes.html'
 
 
@@ -1043,10 +1042,7 @@ def print_mentor_ede_compensation_form(request, pk):
 
 
 def print_klass_list(request):
-     query =  Klass.objects.all(
-         ).annotate(num_students=Count(Case(When(student__archived=False, then=1)))
-         ).filter(num_students__gt=0
-         ).order_by('section', 'name')
+     query =  Klass.active.order_by('section', 'name')
 
      filename = 'archive_RolesDeClasses.zip'
      path = os.path.join(tempfile.gettempdir(), filename)