diff --git a/src/agenda_culturel/filters.py b/src/agenda_culturel/filters.py
index 5ca2786..31ad8ba 100644
--- a/src/agenda_culturel/filters.py
+++ b/src/agenda_culturel/filters.py
@@ -142,6 +142,13 @@ class EventFilter(django_filters.FilterSet):
         p = self.get_cleaned_data("position")
         if not isinstance(d, str) or not isinstance(p, ReferenceLocation):
             return parent
+        try:
+            d = float(d)
+        except ValueError:
+            return parent
+        if d <= 0:
+            return parent
+
         p = p.location
 
         return parent.exclude(exact_location=False).filter(exact_location__location__distance_lt=(p, D(km=d)))