diff --git a/src/index.ts b/src/index.ts
index a01236f..83b0fe9 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -4,7 +4,7 @@ import UAParser from 'ua-parser-js'
 // Get the user ID stored in the client, if it does not exist, make a random one, save it in the client, and return it.
 const getUserId = (event: MCEvent) => {
   const { client } = event
-  let userId = client.get('user_id')
+  let userId = event.payload.user_id || client.get('user_id')
   if (!userId) {
     userId = crypto.randomUUID()
     client.set('user_id', userId, { scope: 'infinite' })