diff --git a/CHANGELOG.md b/CHANGELOG.md
index be440b5..e2472b3 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
+## 4.0.0 (2024-05-15)
 
 ### Fixed
 
diff --git a/package.json b/package.json
index 7a85630..f312163 100644
--- a/package.json
+++ b/package.json
@@ -38,4 +38,4 @@
     "mocha": "^10.2.0",
     "postcss-scss": "^4.0.9"
   }
-}
+}
\ No newline at end of file