diff --git a/program/views.py b/program/views.py
index 97ca0648d5f3350d84af7a7d206ad753a4484404..a47f5cb13cc52e5b54b0c3431acc527af487a110 100644
--- a/program/views.py
+++ b/program/views.py
@@ -1332,7 +1332,12 @@ class APITimeSlotViewSet(
     def update(self, request, *args, **kwargs):
         show_pk = get_values(self.kwargs, "show_pk")
         timeslot = self.get_object()
-        serializer = TimeSlotSerializer(timeslot, data=request.data)
+        serializer = TimeSlotSerializer(
+            timeslot,
+            context={"request": request},  # the serializer needs the request in the context
+            data=request.data,
+        )
+
         if serializer.is_valid(raise_exception=True):
             serializer.save()