Best Practices: Assigning a class to a variable for readability in Ruby

Question

I recently found myself writing the following:

task :spec do |t, args|
  require_relative 'spec/helper'
  helper = Library::Specs::Helper
  helper.start_coverage
  if condition
    helper.do_something(foo)
  else
    arr.each do |el|
      helper.do_something(el)
    end
  end
end

My question is: is it bad practice to assign the name of a class to a variable to save space? Clearly, it makes the code much terser and readable. Are there any downsides?