diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2c8437f..43cf808 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,11 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
-* Deriving `Serialize` for `IIR` and `IIR (int)` to support miniconf updates.
-
 ### Changed
 ### Removed
 
+## [0.4.0] - 2021-12-13
+
+### Added
+* Deriving `Serialize` for `IIR` and `IIR (int)` to support miniconf updates.
+
 ## [0.3.0] - 2021-11-02
 
 ### Removed
@@ -27,7 +30,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 Library initially released on crates.io
 
-[Unreleased]: https://github.com/quartiq/idsp/compare/v0.3.0...HEAD
+[Unreleased]: https://github.com/quartiq/idsp/compare/v0.4.0...HEAD
+[0.4.0]: https://github.com/quartiq/idsp/releases/tag/v0.4.0
 [0.3.0]: https://github.com/quartiq/idsp/releases/tag/v0.3.0
 [0.2.0]: https://github.com/quartiq/idsp/releases/tag/v0.2.0
 [0.1.0]: https://github.com/quartiq/idsp/releases/tag/v0.1.0
diff --git a/Cargo.toml b/Cargo.toml
index 2894040..b42695c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "idsp"
-version = "0.3.0"
+version = "0.4.0"
 resolver = "2"
 authors = ["Robert Jördens <rj@quartiq.de>"]
 edition = "2018"