diff --git a/CHANGES.rst b/CHANGES.rst
index 52f0f25..bbe5043 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,7 +1,7 @@
 Changes
 =======
 
-Version 0.4.0 (UNRELEASED)
+Version 0.4.0 (2024-08-22)
 --------------------------
 
 - Adds support for Python 3.11 and 3.12.
diff --git a/cernopendata_client/version.py b/cernopendata_client/version.py
index 87d228f..ccebe9d 100644
--- a/cernopendata_client/version.py
+++ b/cernopendata_client/version.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # This file is part of cernopendata-client.
 #
-# Copyright (C) 2019, 2020, 2022 CERN.
+# Copyright (C) 2019, 2020, 2022, 2024 CERN.
 #
 # cernopendata-client is free software; you can redistribute it and/or modify
 # it under the terms of the GPLv3 license; see LICENSE file for more details.
@@ -14,4 +14,4 @@
 
 from __future__ import absolute_import, print_function
 
-__version__ = "0.3.0"
+__version__ = "0.4.0"