diff -r 992882cef7e1 -r 9b3577796291 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Tue Mar 28 14:40:13 2017 -0700
+++ b/mercurial/cmdutil.py	Sat Mar 25 09:39:07 2017 +0100
@@ -1155,6 +1155,8 @@
 
 def _changesetlabels(ctx):
     labels = ['log.changeset', 'changeset.%s' % ctx.phasestr()]
+    if ctx.obsolete():
+        labels.append('changeset.obsolete')
     if ctx.troubled():
         labels.append('changeset.troubled')
         for trouble in ctx.troubles():