--- a/hgext/obsolete.py	Sun Jul 29 17:10:43 2012 +0200
+++ b/hgext/obsolete.py	Sun Jul 29 17:25:47 2012 +0200
@@ -128,7 +128,7 @@
     Changeset is hidden.
     """
     args = revset.getargs(x, 0, 0, 'hidden takes no argument')
-    return [r for r in subset if r in repo.changelog.hiddenrevs]
+    return [r for r in subset if r in repo.hiddenrevs]
 
 def revsetobsolete(repo, subset, x):
     """``obsolete()``