fastercsv error with ruby 1.9.2

I have an existing rails application I'm running on ruby 1.9.2 and linux its rails version is

rails 2.3.8

and it has a GEMFILE as well, in its vendor/gems directory it has 'fastercsv-1.5.4' gem
and in its migrations (in two migrations) it has required the gem 'fastercsv'

require 'fastercsv'

But when I do

rake db:migrate 

it fails the migration claiming

"Please switch to Ruby 1.9's standard CSV library. It's FasterCSV plus support for Ruby 1.9's m17n encoding engine."

and I have found out the message comes from gems 'faster_csv.rb' file. as it has a condition to check the ruby version

if RUBY_VERSION >= "1.9"

  class FasterCSV
    def self.const_missing(*_)
      raise NotImplementedError, "Please switch to Ruby 1.9's standard CSV "  +
                                 "library.  It's FasterCSV plus support for " +
                                 "Ruby 1.9's m17n encoding engine."
    end

    def self.method_missing(*_)
      const_missing
    end

    def method_missing(*_)
      self.class.const_missing
    end
  end

-- and more code

Can someone tell me how to fix this issue. Please note 'fastercsv' has not been added to the GEMFILE.

I found the answer to my question

Its based on this post

What is Ruby 1.9 standard CSV library?

and as the solution i had to

require 'csv'

instead of

require 'fastercsv'

and change the FasterCSV to CSV