diff --git a/lib/providers/meta-client.ts b/lib/providers/meta-client.ts
index 9d9c4a1..ae8ead1 100644
--- a/lib/providers/meta-client.ts
+++ b/lib/providers/meta-client.ts
@@ -313,7 +313,7 @@ export class MetaAIClient {
         const externalConversationId = crypto.randomUUID();
         const timestamp = Date.now();
         const randomPart = Math.floor(Math.random() * 4194304); // 22 bits
-        const offlineThreadingId = ((BigInt(timestamp) << 22n) | BigInt(randomPart)).toString();
+        const offlineThreadingId = ((BigInt(timestamp) << BigInt(22)) | BigInt(randomPart)).toString();
 
         // Store for polling
         this.session.externalConversationId = externalConversationId;