diff --git a/CHANGELOG.md b/CHANGELOG.md
index 83bfb45..34cba61 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,9 @@ The format 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]
+<!-- ## [Unreleased] -->
+
+## [0.4.0] - 2025-08-27
 
 ### Added
 
@@ -44,7 +46,8 @@ and this project adheres to
 
 Initial release.
 
-[unreleased]: https://github.com/cometsh/atex/compare/v0.3.0...HEAD
+[unreleased]: https://github.com/cometsh/atex/compare/v0.4.0...HEAD
+[0.4.0]: https://github.com/cometsh/atex/releases/tag/v0.4.0
 [0.3.0]: https://github.com/cometsh/atex/releases/tag/v0.3.0
 [0.2.0]: https://github.com/cometsh/atex/releases/tag/v0.2.0
 [0.1.0]: https://github.com/cometsh/atex/releases/tag/v0.1.0
diff --git a/mix.exs b/mix.exs
index f779f21..a843caf 100644
--- a/mix.exs
+++ b/mix.exs
@@ -1,7 +1,7 @@
 defmodule Atex.MixProject do
   use Mix.Project
 
-  @version "0.3.0"
+  @version "0.4.0"
   @github "https://github.com/cometsh/atex"
   @tangled "https://tangled.sh/@comet.sh/atex"