diff --git a/CHANGELOG.md b/CHANGELOG.md
index be03ff6..ea1d1bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,3 +2,6 @@
 
 All notable changes to the project will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org).
 
+## [1.0.0] - 2021-08-06
+Initial release, for use with version 4.x of the LaunchDarkly PHP SDK.
+