diff --git a/CHANGES b/CHANGES
index c87ae69b09ab62614df0d729c5d1aa801c0d7a0b..19a8721744cdbee5fea9f3f65c036cbda15a6b8a 100644
--- a/CHANGES
+++ b/CHANGES
@@ -38,7 +38,11 @@ o Compiler
 
 o Calendar
 
-  Updated tzdata to 2017c.
+  - Updated tzdata to 2017c.
+
+  - Calendar.TimeRanges.NullTimeRange now has a working __hash().
+    The expression ([ Calendar.TimeRandes.nulltimerange : 17 ])
+    no longer gives a backtrace.
 
 o Crypto.CCM