diff --git a/lib/webPush.js b/lib/webPush.js
index 4a460681..c4daa44a 100644
--- a/lib/webPush.js
+++ b/lib/webPush.js
@@ -85,6 +85,9 @@ const sendNotification = (subscription, payload) => {
 
 async function sendUserNotification (userId, notification) {
   try {
+    if (!userId) {
+      throw new Error('user id is required')
+    }
     notification.data ??= {}
     if (notification.item) {
       notification.data.url ??= await createItemUrl(notification.item)