Minor improvement to `WritableObjectId`
diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
index f8724a9..f868edf 100644
--- a/release-notes/VERSION-2.x
+++ b/release-notes/VERSION-2.x
@@ -10,7 +10,9 @@
  (reported by Thomas K)
 #2221: `DeserializationProblemHandler.handleUnknownTypeId()` returning `Void.class`,
   enableDefaultTyping causing NPE
- (repoted by MeyerNils@github)
+ (reported by MeyerNils@github)
+- Prevent String coercion of `null` in `WritableObjectId` when calling `JsonGenerator.writeObjectId()`,
+  mostly relevant for formats like YAML that have native Object Ids
 
 2.9.8 (15-Dec-2018)