diff --git a/ChangeLog b/ChangeLog
index 7d1824e475..74a9998a51 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Apr 23 13:21:24 2016  Yuichiro Kaneko  <yui-knk@ruby-lang.org>
+
+	* NEWS: Add descriptions for DateTime#to_time updates.
+	  [Bug #12189]
+
 Sat Apr 23 11:21:27 2016  Marcus Stollsteimer  <sto.mar@web.de>
 
 	* ext/date/date_core.c (Init_date_core): [DOC] Convert DateTime
diff --git a/NEWS b/NEWS
index 67b4f25a88..eb048ad179 100644
--- a/NEWS
+++ b/NEWS
@@ -84,6 +84,12 @@ with all sufficient information, see the ChangeLog file or Redmine
   Ruby's sum method should be mostly compatible but it is impossible to
   be perfectly compatible with all of them.
 
+=== Stdlib compatibility issues (excluding feature bug fixes)
+
+* DateTime
+
+  * DateTime#to_time now preserves timezone.  [Bug #12189]
+
 === C API updates
 
 * ruby_show_version() will no longer exits the process, if