diff --git a/app.js b/app.js
index bf092c8..7140d82 100644
--- a/app.js
+++ b/app.js
@@ -118,7 +118,7 @@ peers.on('connection', async socket => {
   })
 
   socket.on('createRoom', async ({ callId }, callback) => {
-    if (videoCalls[callId]?.router === undefined) {
+    if (videoCalls[callId] && videoCalls[callId].router === undefined) {
       console.log('[createRoom] callId', callId);
       videoCalls[callId].router = await worker.createRouter({ mediaCodecs });
       console.log(`[createRoom] Router ID: ${videoCalls[callId].router.id}`)