diff --git a/CHANGELOG.md b/CHANGELOG.md
index f68ff7c92..f049e10c1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Unreleased
 
+## Added
+* Refined ABI type-check on assignment. ([#540](https://github.com/algorand/pyteal/pull/540))
+
 ## Fixed
 * Erroring on constructing an odd length hex string. ([#539](https://github.com/algorand/pyteal/pull/539))