diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8be5beab..4440524a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,11 @@
 # Optimizely Ruby SDK Changelog
 
 
-## Unreleased
+## 4.0.0
+August 4, 2022
 
-### Changes:
-* Breaking change: Changed official supported versions of Ruby to 2.7, 3.0 and 3.1
+### Breaking Changes:
+* Changed official supported versions of Ruby to 2.7, 3.0 and 3.1
 
 ## 3.10.1
 February 2, 2022
diff --git a/lib/optimizely/version.rb b/lib/optimizely/version.rb
index d70b8b65..81851e7d 100644
--- a/lib/optimizely/version.rb
+++ b/lib/optimizely/version.rb
@@ -17,5 +17,5 @@
 #
 module Optimizely
   CLIENT_ENGINE = 'ruby-sdk'
-  VERSION = '3.10.1'
+  VERSION = '4.0.0'
 end