diff --git a/CHANGELOG.md b/CHANGELOG.md
index edbc5a1e..234612e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,19 @@
+# Changelog
+
+All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
+
+## [0.4.0](https://github.com/urbica/martin/compare/v0.3.0...v0.4.0) (2019-09-30)
+
+
+### ⚠ BREAKING CHANGES
+
+* renamed CLI args: keep_alive -> keep-alive, listen_addresses ->
+listen-addresses, pool_size -> pool-size
+
+### Bug Fixes
+
+* 🐛 use dashes in CLI args instead of underscore ([13bec40](https://github.com/urbica/martin/commit/13bec40)), closes [#21](https://github.com/urbica/martin/issues/21)
+
 <a name="0.3.0"></a>
 
 ## 0.3.0 (2019-03-16)