diff --git a/CHANGELOG.md b/CHANGELOG.md
index d8adb4df..2e28978a 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,23 @@ All notable changes to this project will be documented in this file.
 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).
 
+## [4.0.0](https://github.com/unzerdev/php-sdk/compare/3.15.0..4.0.0)
+
+### Added
+
+* Add `company` field to `\UnzerSDK\Resources\EmbeddedResources\Address` class.
+* Add PHP 8.5 to supported versions in `composer.json`.
+
+### Changed
+
+* Allow `null` return for `getCompany()` in `\UnzerSDK\Resources\EmbeddedResources\Address`.
+* Remove deprecated `curl_close` and `\ReflectionMethod::setAccessible` calls to address PHP 8.5 deprecation warnings.
+* Drop support for PHP 7.4 and PHP 8.0.
+
+### Deprecated
+
+* Mark `\UnzerSDK\Resources\PaymentTypes\Giropay` as deprecated.
+
 ## [3.15.0](https://github.com/unzerdev/php-sdk/compare/3.14.0..3.15.0)
 
 ### Added
diff --git a/src/Unzer.php b/src/Unzer.php
index 46501b00..846010d8 100644
--- a/src/Unzer.php
+++ b/src/Unzer.php
@@ -59,7 +59,7 @@ class Unzer implements
     public const BASE_URL = 'api.unzer.com';
     public const API_VERSION = ApiVersions::V1;
     public const SDK_TYPE = 'UnzerPHP';
-    public const SDK_VERSION = '3.15.0';
+    public const SDK_VERSION = '4.0.0';
 
     /** @var string $key */
     private $key;