Fixed #1552
diff --git a/release-notes/VERSION b/release-notes/VERSION
index 25080c0..19f1bea 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -62,6 +62,8 @@
  (reported by Lyor G)
 #1550: Unexpected behavior with `@JsonInclude(JsonInclude.Include.NON_EMPTY)` and
  `java.util.Date` serialization
+#1552: Map key converted to byte array is not serialized as base64 string
+ (reported by nmatt@github)
 #1554: Support deserialization of `Shape.OBJECT` ("as POJO") for `Map`s (and map-like types)
 
 2.8.8 (not yet released)