Fix #604
diff --git a/release-notes/VERSION b/release-notes/VERSION
index 4174b6f..f64bb20 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -17,6 +17,7 @@
  (reported by Jerbell@github)
 #592: Wrong `TokenBuffer` delegate deserialization using `@JsonCreator`
  (reported by Eugene L)
+#604: `Map` deserializers not being cached, causing performance problems
 - Minor fix to `EnumSerializer` regarding detection "serialize using index"
 - Minor fix to number serializers, to call proper callback for schema generation