diff --git a/membershipworks/models.py b/membershipworks/models.py
index 9079164..12da651 100644
--- a/membershipworks/models.py
+++ b/membershipworks/models.py
@@ -448,32 +448,37 @@ class EventExtQuerySet(models.QuerySet["EventExt"]):
 
 class EventExtManager(models.Manager["EventExt"]):
     def get_queryset(self) -> models.QuerySet["EventExt"]:
-        return EventExtQuerySet(self.model, using=self._db).annotate(
-            meeting_times__count=Subquery(
-                EventMeetingTime.objects.filter(event=OuterRef("pk"))
-                .values("event__pk")
-                .annotate(d=Count("pk"))
-                .values("d")[:1],
-                output_field=models.IntegerField(),
-            ),
-            duration=Subquery(
-                EventMeetingTime.objects.filter(event=OuterRef("pk"))
-                .values("event__pk")
-                .annotate(d=Sum("duration"))
-                .values("d")[:1],
-                output_field=models.DurationField(),
-            ),
-            person_hours=ExpressionWrapper(
-                ExpressionWrapper(F("duration"), models.IntegerField()) * F("count"),
-                models.DurationField(),
-            ),
+        return (
+            super()
+            .get_queryset()
+            .annotate(
+                meeting_times__count=Subquery(
+                    EventMeetingTime.objects.filter(event=OuterRef("pk"))
+                    .values("event__pk")
+                    .annotate(d=Count("pk"))
+                    .values("d")[:1],
+                    output_field=models.IntegerField(),
+                ),
+                duration=Subquery(
+                    EventMeetingTime.objects.filter(event=OuterRef("pk"))
+                    .values("event__pk")
+                    .annotate(d=Sum("duration"))
+                    .values("d")[:1],
+                    output_field=models.DurationField(),
+                ),
+                person_hours=ExpressionWrapper(
+                    ExpressionWrapper(F("duration"), models.IntegerField())
+                    * F("count"),
+                    models.DurationField(),
+                ),
+            )
         )
 
 
 class EventExt(Event):
     """Extension of `Event` to capture some fields not supported in MembershipWorks"""
 
-    objects = EventExtManager()
+    objects = EventExtManager.from_queryset(EventExtQuerySet)()
 
     instructor = models.ForeignKey(
         EventInstructor, on_delete=models.PROTECT, null=True, blank=True