diff --git a/CHANGELOG.md b/CHANGELOG.md
index 16e32ba..9fb23dd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ This file documents recent notable changes to this project. The format of this
 file is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and
 this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [0.4.0] - 2026-08-14
 
 ### Added
 
@@ -346,7 +346,7 @@ contract has never run in a consumer once.
   and would leave every pull request pinned to one release and filled from
   another. `scripts/test_sync.py` covers it.
 
-[Unreleased]: https://github.com/aicers/agent-instructions/compare/0.3.1...main
+[0.4.0]: https://github.com/aicers/agent-instructions/compare/0.3.1...0.4.0
 [0.3.1]: https://github.com/aicers/agent-instructions/compare/0.3.0...0.3.1
 [0.3.0]: https://github.com/aicers/agent-instructions/compare/0.2.1...0.3.0
 [0.2.1]: https://github.com/aicers/agent-instructions/compare/0.2.0...0.2.1