diff --git a/src/Socket/socket.ts b/src/Socket/socket.ts
index a3b4f1d..45323d7 100644
--- a/src/Socket/socket.ts
+++ b/src/Socket/socket.ts
@@ -524,6 +524,11 @@ export const makeSocket = ({
         const reason = +(node.attrs.reason || 500)
         end(new Boom('Connection Failure', { statusCode: reason, data: node.attrs }))
     })
+
+    ws.on('CB:ib,,downgrade_webclient', () => {
+        end(new Boom('Multi-device beta not joined', { statusCode: DisconnectReason.notJoinedBeta }))
+    })
+
     process.nextTick(() => {
         ev.emit('connection.update', { connection: 'connecting', receivedPendingNotifications: false, qr: undefined })
     })
diff --git a/src/Types/index.ts b/src/Types/index.ts
index 1c69c2d..6eca814 100644
--- a/src/Types/index.ts
+++ b/src/Types/index.ts
@@ -60,7 +60,8 @@ export enum DisconnectReason {
     timedOut = 408,
 	loggedOut = 401,
     badSession = 500,
-    restartRequired = 410
+    restartRequired = 410,
+    notJoinedBeta = 403
 }
 
 export type WAInitResponse = {