diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a22d315..9422f669 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@
 **Fixed**
 - Support promise based tokenGetter in JwtHelperService [\#748](https://github.com/auth0/angular2-jwt/pull/748) ([frederikprijck](https://github.com/frederikprijck))
 
+**Note**: this fixes incorrect behavior that currently exists in the SDK when using async token retrieval, but causes a breaking change in terms of the types, as `decodeToken`, `getTokenExpirationDate` and `isTokenExpired` now returns `T | Promise<T>` instead of just `T`. Promises have always been supported, but the API never properly considered for that in the `JwtHelperService`.
+
 ## Version [5.1.0](https://github.com/auth0/angular2-jwt/tags/v5.1.0)
 
 [Full Changelog](https://github.com/auth0/angular2-jwt/compare/v5.0.2..v5.1.0)