diff --git a/CHANGELOG.md b/CHANGELOG.md
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--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v0.21.0 (Unreleased)
+
+Support [`handlers.handlerSchema`](https://github.com/aws-cloudformation/cloudformation-resource-schema#handlers).
+
 ## v0.20.0 (December 19, 2022)
 
 Support [`arrayType`](https://github.com/aws-cloudformation/cloudformation-resource-schema#arraytype).