diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8a4fe07..58b5842 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,9 @@ This projects adheres to [Semantic Versioning](http://semver.org/) and [Keep a C
 ## [Unreleased][unreleased]
 -
 
+## [4.2.1] - 2022-09-27
+- Update to `wp-pay/core` version `^4.4`.
+
 ## [4.2.0] - 2022-09-26
 - Updated payment methods registration.
 - Updated for Sisow via Buckaroo integration (pronamic/wp-pronamic-pay-sisow#3).
@@ -119,7 +122,8 @@ This projects adheres to [Semantic Versioning](http://semver.org/) and [Keep a C
 ## [1.0.0] - 2015-01-19
 - First release.
 
-[unreleased]: https://github.com/wp-pay-gateways/buckaroo/compare/4.2.0...HEAD
+[unreleased]: https://github.com/wp-pay-gateways/buckaroo/compare/4.2.1...HEAD
+[4.2.1]: https://github.com/pronamic/wp-pronamic-pay-buckaroo/compare/4.2.0...4.2.1
 [4.2.0]: https://github.com/pronamic/wp-pronamic-pay-buckaroo/compare/4.1.0...4.2.0
 [4.1.0]: https://github.com/wp-pay-gateways/buckaroo/compare/4.0.0...4.1.0
 [4.0.0]: https://github.com/wp-pay-gateways/buckaroo/compare/3.0.2...4.0.0
diff --git a/composer.json b/composer.json
index 615c2f9..26cc150 100644
--- a/composer.json
+++ b/composer.json
@@ -40,7 +40,7 @@
 	"require": {
 		"php": ">=5.6.20",
 		"pronamic/wp-http": "^1.1",
-		"wp-pay/core": "^4.0"
+		"wp-pay/core": "^4.4"
 	},
 	"require-dev": {
 		"bamarni/composer-bin-plugin": "^1.4",
diff --git a/package.json b/package.json
index c6ff42a..77a9ec2 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "buckaroo",
-  "version": "4.2.0",
+  "version": "4.2.1",
   "description": "Buckaroo driver for the WordPress payment processing library.",
   "repository": {
     "type": "git",
diff --git a/pronamic-pay-buckaroo.php b/pronamic-pay-buckaroo.php
index 92478bc..2436595 100644
--- a/pronamic-pay-buckaroo.php
+++ b/pronamic-pay-buckaroo.php
@@ -4,7 +4,7 @@
  * Plugin URI: https://www.pronamic.eu/plugins/pronamic-pay-buckaroo/
  * Description: Extend the Pronamic Pay plugin with the Buckaroo gateway to receive payments through a variety of WordPress plugins.
  *
- * Version: 4.1.0
+ * Version: 4.2.1
  * Requires at least: 4.7
  *
  * Author: Pronamic