diff --git a/program/services.py b/program/services.py
index 0ec3c79f203bd86fcf49cc2befd5547b96e5af78..8f0af2436436c378da1b7ab03e4bb9cb8540b733 100644
--- a/program/services.py
+++ b/program/services.py
@@ -373,7 +373,7 @@ def make_conflicts(data: ScheduleData, schedule_pk: int | None, show_pk: int) ->
             and new_schedule.last_date > existing_schedule.last_date
         ):
             last_timeslot = (
-                TimeSlot.objects.filter(schedule=existing_schedule).order_by("start").reverse()[0]
+                TimeSlot.objects.filter(schedule=existing_schedule).order_by("start").last()
             )
             schedule_copy.first_date = last_timeslot.start.date() + timedelta(days=1)