module I18n::Backend::InterpolationCompiler::Compiler

def compile_if_an_interpolation(string)
  if interpolated_str?(string)
    string.instance_eval <<-RUBY_EVAL, __FILE__, __LINE__
      def i18n_interpolate(v = {})
        "#{compiled_interpolation_body(string)}"
      end
    RUBY_EVAL
  end
  string
end