diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5230c738..b4567e44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 4.0.0 (December 30th, 2021)
+## 4.0.1 (December 30th, 2021)
 
 Bugfixes:
 - ab_test must return metadata on error or if split is disabled/excluded user (@andrehjr, #622)
diff --git a/lib/split/version.rb b/lib/split/version.rb
index dbb9b4c0..037a710e 100644
--- a/lib/split/version.rb
+++ b/lib/split/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Split
-  VERSION = "4.0.0"
+  VERSION = "4.0.1"
 end