diff --git a/backend/supabase/push_subscriptions.sql b/backend/supabase/push_subscriptions.sql
index 62a29fc..c583d7f 100644
--- a/backend/supabase/push_subscriptions.sql
+++ b/backend/supabase/push_subscriptions.sql
@@ -1,6 +1,6 @@
 create table push_subscriptions (
     id serial primary key,
-    user_id TEXT references users(id), -- optional if per-user
+    user_id TEXT references users(id) on delete cascade,
     endpoint text not null unique,
     keys jsonb not null,
     created_at timestamptz default now()