diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5665a29b..1262cf45 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Fixed
 
 * Clear error indicator when the exception is handled on the Rust side. [#719](https://github.com/PyO3/pyo3/pull/719)
+* Fixed unsoundness of subclassing. [#683](https://github.com/PyO3/pyo3/pull/683).
 
 ### Removed