Is there a command to undo a update

Is there a way to undo an bzr update, without having to know the revision of my checkout before the update is done?

Eg: If my checkout is at revno 10 and an update causes it to bump up to revno 15.
I would have to do a bzr uncommit -r10 --local, to undo the update. But this would require me to remember the revno before updating (revno 10) or look in the log for the last revno that I contributed. This is kindof cumbersome and hence the above question.