diff --git a/release-notes/VERSION b/release-notes/VERSION
index b7f0526..7536a16 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -34,6 +34,9 @@
  (requested by herau@github)
 #576: Add fluent API for adding mixins
  (contributed by Adam S, adstro@github)
+#597: Improve error messaging for cases where JSON Creator returns null (which
+  is illegal)
+ (contributed by Aurelien L)
 - Allow use of `Shape.ARRAY` for Enums, as an alias to 'use index'
 - Start using `JsonGenerator.writeStartArray(int)` to help data formats
   that benefit from knowing number of elements in arrays (and would otherwise