--- a/mercurial/commands.py	Mon Jan 21 12:58:59 2013 -0600
+++ b/mercurial/commands.py	Mon Jan 21 13:47:10 2013 -0600
@@ -5961,7 +5961,12 @@
     # with no argument, we also move the current bookmark, if any
     movemarkfrom = None
     if rev is None:
-        movemarkfrom = repo['.'].node()
+        curmark = repo._bookmarkcurrent
+        if bookmarks.iscurrent(repo):
+            movemarkfrom = repo['.'].node()
+        elif curmark:
+            ui.status(_("updating to active bookmark %s\n") % curmark)
+            rev = curmark
 
     # if we defined a bookmark, we have to remember the original bookmark name
     brev = rev