diff --git a/CHANGELOG.md b/CHANGELOG.md
index e70c579..cb201f1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,15 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-[Unreleased]: https://github.com/althonos/orthoani/compare/v0.3.2...HEAD
+[Unreleased]: https://github.com/althonos/orthoani/compare/v0.4.0...HEAD
+
+## [v0.4.0] - 2020-06-26
+[v0.4.0]: https://github.com/althonos/orthoani/compare/v0.3.2...v0.4.0
+### Changed
+- Entire sequences smaller than the given blocksize will be padded with *N*.
+- `biopython` requirement was relaxed to `v1.73`.
+### Fixed
+- Code using builtin API not available in Python3.5.
 
 ## [v0.3.2] - 2020-06-24
 [v0.3.2]: https://github.com/althonos/orthoani/compare/v0.3.1...v0.3.2
diff --git a/orthoani/_version.txt b/orthoani/_version.txt
index d15723f..1d0ba9e 100644
--- a/orthoani/_version.txt
+++ b/orthoani/_version.txt
@@ -1 +1 @@
-0.3.2
+0.4.0