diff --git a/CHANGELOG.md b/CHANGELOG.md
index a0a24870..684365f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ versions.
 - Floats can be decoded from integers (#641, fixes #603)
 - Resource types can implement and use dynamic calls on NIF version 2.16 (#635)
 - `Encoder` and `Decoder` implementations for `Box<T>` (#644)
+- `Reference` type and `env.make_ref()` function (#657)
 
 ### Fixed