no such file to load -- spec

While trying to use Goto Alternate File (⌃⇧↓) in TextMate's Cucumber Bundle I was seeing an error like this:
no such file to load -- spec

that was pointing to line 20 of:
~/Library/Application\ Support/TextMate/Bundles/Cucumber.tmbundle/Support/lib/cucumber/mate.rb

That line reads like this:

I changed it to:

Reloaded bundles (Bundles→Bundle Editor→Reload Bundles). And now things are working fine. My guess is RSpec 2 now goes by 'rspec' instead of 'spec'.