diff --git a/service/views.py b/service/views.py
index 5b3888b..5361df6 100644
--- a/service/views.py
+++ b/service/views.py
@@ -287,9 +287,10 @@ class PlacementPointViewSet(ReadOnlyModelViewSet):
     @action(detail=False, methods=['put'])
     def update_fact(self, request):
         point_id = request.GET.get('postamat_id')
-        fact = request.GET.get('fact')
-        if not point_id or not fact or not fact.isdigit():
+        fact_ = request.GET.get('fact')
+        if not point_id or not fact_ or not fact_.isdigit():
             return Response(status=HTTPStatus.BAD_REQUEST)
+        fact = float(fact_) if fact_ else None
         qs = models.PlacementPoint.objects.filter(postamat_id=point_id)
         if not qs:
             return Response(status=HTTPStatus.NOT_FOUND)