diff --git a/CHANGES.rst b/CHANGES.rst
index 975feb77..28474887 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,3 +4,6 @@
 - Create package and import code from jwst.datamodels. [#1]
 
 - Remove stdatamodels.open. [#2]
+
+- Fix validation behavior when an object with nested None values is
+  assigned to a DataModel attribute. [#45]