Missing dependency in Gemfile for multi_json

[ketiko]

/ruby-1.9.3-p194/gems/toggl-0.3.0/lib/toggl.rb:4:in `require': cannot load such file -- multi_json (LoadError)
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/gems/toggl-0.3.0/lib/toggl.rb:4:in `<top (required)>'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/gems/toggl-0.3.0/bin/toggl:6:in `require'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/gems/toggl-0.3.0/bin/toggl:6:in `<top (required)>'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/bin/toggl:19:in `load'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/bin/toggl:19:in `<main>'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `eval'
    from /home/ketiko/.rvm/gems/ruby-1.9.3-p194/bin/ruby_noexec_wrapper:14:in `<main>'

lib/toggl.rb has a

require 'multi_json'

But that gem is not installed by the gem.