diff --git a/CHANGELOG.md b/CHANGELOG.md
index 04769f8..8011b0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ 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).
 
+## [0.4.0](https://github.com/toon-format/toon-rust/compare/v0.3.7...v0.4.0) - 2025-11-25
+
+### Added
+
+- update to TOON v3.0 spec (breaking change) ([#36](https://github.com/toon-format/toon-rust/pull/36))
+
 ## [0.3.7](https://github.com/toon-format/toon-rust/compare/v0.3.6...v0.3.7) - 2025-11-21
 
 ### Fixed
diff --git a/Cargo.toml b/Cargo.toml
index 433d668..82bdbc2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "toon-format"
-version = "0.3.7"
+version = "0.4.0"
 edition = "2021"
 authors = [
     "Johann Schopplich <hello@johannschopplich.com>",