diff --git a/CHANGELOG.md b/CHANGELOG.md
index aeba130..4be452b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Changelog
 
-## Unreleased
+## 0.4.0 - 2023-10-14
 
 ### Breaking changes
 
@@ -53,6 +53,7 @@ case in mind and aren't generally useful have been removed:
 ### Other
 
 * Add section to README on fitting other score functions than the likelihood
+* Add changelog with all version changes up to this one
 
 ## 0.3.2 - 2021-03-26
 
diff --git a/pyproject.toml b/pyproject.toml
index 1b11798..33b2dc2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pykelihood"
-version = "0.3.2"
+version = "0.4.0"
 description = "Intuitive syntax for complex statistical model fitting and parameter sensitivity analysis."
 authors = ["Ophélia Miralles <ophelia.miralles@epfl.ch>"]
 license = "MIT"