diff --git a/CHANGELOG.md b/CHANGELOG.md
index 716b99d9fc29..c884e80e531d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [4.0.20]
+
+[4.0.20]: https://github.com/microsoft/CCF/releases/tag/ccf-4.0.20
+
+### Base image
+
+- Updated container base image.
+
 ## [4.0.19]
 
 [4.0.19]: https://github.com/microsoft/CCF/releases/tag/ccf-4.0.19