diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..283c4f2
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,23 @@
+# Changelog
+
+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]
+
+## [0.4.0](https://github.com/HellButcher/tinybox-rs/compare/v0.3.1...v0.4.0) - 2026-10-04
+
+### Fixed
+
+- reduced UB
+- use Layout::for_value_raw to avoid creating dangeling references
+
+### Other
+
+- update pipeline
+- automatic clippy fixes
+- update github actions
+- use sparse crates.io index
+- update README.md
diff --git a/Cargo.toml b/Cargo.toml
index c51390f..b7829dc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tinybox"
-version = "0.3.1"
+version = "0.4.0"
 description = "Like `Box`, but with an optimization that avoids allocations for small data-structures"
 authors = ["Christoph Hommelsheim <main@chommel.eu>"]
 license = "MIT OR Apache-2.0"