diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46c2f75b..19c6651c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# Unreleased
+
+- Add Puma to dependencies ([#214](https://github.com/alphagov/govuk_app_config/pull/214)).
+
 # 4.0.1
 
 - Update Content Security Policy with new klick2contact.com subdomain ([#213](https://github.com/alphagov/govuk_app_config/pull/213)).
diff --git a/lib/govuk_app_config/version.rb b/lib/govuk_app_config/version.rb
index 7979e8fb..73154326 100644
--- a/lib/govuk_app_config/version.rb
+++ b/lib/govuk_app_config/version.rb
@@ -1,3 +1,3 @@
 module GovukAppConfig
-  VERSION = "4.1.0".freeze
+  VERSION = "4.0.1".freeze
 end