diff --git a/lib/tasks/transcribe.js b/lib/tasks/transcribe.js
index e636d8c4..a25c7266 100644
--- a/lib/tasks/transcribe.js
+++ b/lib/tasks/transcribe.js
@@ -902,6 +902,8 @@ class TaskTranscribe extends SttTask {
   // We need to keep track the fallback is happened for each endpoint
   // override the canFallback and _initFallback methods to make sure that
   // we only fallback once per endpoint
+  // we want to keep track this on task level instead of endpoint level
+  // because the endpoint instance is used across multiple tasks.
   canFallback(ep) {
     const isHandledByPrimaryProvider = ep === this.ep ?
       this.isHandledByPrimaryProviderForEp1 : ep === this.ep2 ?