diff --git a/Misc/NEWS b/Misc/NEWS
index 7c66a66..f7c1302 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -42,6 +42,10 @@
 Library
 -------
 
+- Issue #6637: defaultdict.copy() did not work when the default factory
+  was left unspecified.  Also, the eval/repr round-trip would fail when
+  the default_factory was None.
+
 - Issue #2715: Remove remnants of Carbon.File from binhex module.
 
 - Issue #6595: The Decimal constructor now allows arbitrary Unicode