diff --git a/passerelle/contrib/caluire_axel/schemas.py b/passerelle/contrib/caluire_axel/schemas.py
index ca9c3604..f69cc52c 100644
--- a/passerelle/contrib/caluire_axel/schemas.py
+++ b/passerelle/contrib/caluire_axel/schemas.py
@@ -178,6 +178,7 @@ CHANGES_SCHEMA = {
                     'booked': copy.deepcopy(boolean_type),
                 },
                 'required': [
+                    'activity_id',
                     'activity_label',
                     'day',
                     'booked',