diff --git a/ChangeLog.2 b/ChangeLog.2
index 9dff59780e0..8c30a11a11d 100644
--- a/ChangeLog.2
+++ b/ChangeLog.2
@@ -28,7 +28,7 @@
 
 	* test/automated/file-notify-tests.el (file-notify-test02-events):
 	Rectify `attribute-change' tests.  There are timing issues with
-	gfilenotify.
+	gfilenotify.  (Bug#21669)
 
 2015-10-16  Paul Eggert  <eggert@cs.ucla.edu>