Fix #56
diff --git a/release-notes/VERSION b/release-notes/VERSION
index a3de549..e72bdec 100644
--- a/release-notes/VERSION
+++ b/release-notes/VERSION
@@ -11,6 +11,10 @@
 === Releases ===
 ------------------------------------------------------------------------
 
+2.6.0 (not yet released)
+
+#56: Improve `ObjectIdGenerators.key()` to handle `null` appropriately by returning `null`
+
 2.5.0 (01-Jan-2015)
 
 #47: Add `@JsonCreator.mode` property to explicitly choose between delegating-