diff --git a/CHANGELOG.md b/CHANGELOG.md
index 83f4dce..7713d9f 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](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+## [4.0.0] - 2024-01-04
+
+- Support PHP 8.1+
+- Update PHPUnit to 8.x
+- Replace `leafo/scssphp` with `scssphp/scssphp`
+
 ## [3.0.14] - 2023-05-05
 
 - Support monolog v3, [#705]