diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a52c3d7f2a3f..2a082d72a81f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -78,6 +78,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ## [Unreleased 2.x]
 ### Added
 - Add metrics for thread_pool task wait time ([#9681](https://github.com/opensearch-project/OpenSearch/pull/9681))
+- Add protobuf support for transport request and response base classes ([#9737](https://github.com/opensearch-project/OpenSearch/pull/9737))
 
 ### Dependencies
 - Bump `peter-evans/create-or-update-comment` from 2 to 3 ([#9575](https://github.com/opensearch-project/OpenSearch/pull/9575))