diff --git a/django_mailbox/models.py b/django_mailbox/models.py
index 69a1d0c..5b7fbbc 100644
--- a/django_mailbox/models.py
+++ b/django_mailbox/models.py
@@ -50,9 +50,9 @@ class MailboxManager(models.Manager):
         return MailboxQuerySet(self.model, using=self._db)
 
 
-class ActiveMailboxManager(models.Manager):
+class ActiveMailboxManager(MailboxManager):
     def get_queryset(self):
-        return MailboxQuerySet(self.model, using=self._db).filter(
+        return super().get_queryset().filter(
             active=True,
         )