diff --git a/chrono/api/views.py b/chrono/api/views.py
index 78b0ee23..0f7f32b5 100644
--- a/chrono/api/views.py
+++ b/chrono/api/views.py
@@ -1867,14 +1867,15 @@ class RecurringFillslots(APIView):
             Booking.objects.filter(primary_booking__in=bookings_to_cancel).update(
                 cancellation_datetime=cancellation_datetime
             )
-            cancelled_events = [
-                get_short_event_detail(
-                    request,
-                    events_by_id[x.event_id],
-                    multiple_agendas=True,
-                )
-                for x in bookings_to_cancel
-            ]
+            if payload.get('include_booked_events_detail'):
+                cancelled_events = [
+                    get_short_event_detail(
+                        request,
+                        events_by_id[x.event_id],
+                        multiple_agendas=True,
+                    )
+                    for x in bookings_to_cancel
+                ]
             cancelled_count = bookings_to_cancel.update(cancellation_datetime=cancellation_datetime)
             # and delete outdated cancelled bookings
             Booking.objects.filter(