diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46f8d46..4e58ce8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ 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]
+## [4.0.0] - 2023-10-16
 
 - DEP: migrate prompting from rich to termcolor
 - API: remove `idfx stamp` command, drop dependency on GitPython
diff --git a/src/idefix_cli/__init__.py b/src/idefix_cli/__init__.py
index 1da6a55..ce1305b 100644
--- a/src/idefix_cli/__init__.py
+++ b/src/idefix_cli/__init__.py
@@ -1 +1 @@
-__version__ = "3.2.1"
+__version__ = "4.0.0"