Paperclip install issues with rails 3

Installed plugin, then ran bundle install and get th开发者_Go百科is...

bundle install
Updating git://github.com/thoughtbot/paperclip.git
fatal: ambiguous argument 'rails3': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions
Git error: command `git rev-parse rails3` in directory /Library/Ruby/Gems/1.8/cache/bundler/git/paperclip-61f74de14812cabc026967a2b2c3ca8cbd2eed69 has failed.
If this error persists you could try removing the cache directory '/Library/Ruby/Gems/1.8/cache/bundler/git/paperclip-61f74de14812cabc026967a2b2c3ca8cbd2eed69'

I'm assuming your gemfile is pointing the paperclip revision to rails3. This is no longer necessary, as the gem is caught up with the current version of Rails.