diff --git a/CHANGELOG.md b/CHANGELOG.md
index 457709e..531073e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 4.x
+
+### 4.0.0
+
+* `$string` parameter is mandatory
+* Added getResponse() method to build PSR-7 response object
+* Removed all custom exceptions 
+
 ## 3.x
 
 ### 3.1.0