diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97506e1..efbdd97 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 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
+## v0.4.0 - 2023-03-02
 ### Added
 - `-diff` flag as an alias for `-d`.
 - `-preface` flag to include contents of another file in the output verbatim.