module I18n::Backend::Fallbacks

def exists?(locale, key, options = EMPTY_HASH)
  return super unless options.fetch(:fallback, true)
  I18n.fallbacks[locale].each do |fallback|
    begin
      return true if super(fallback, key)
    rescue I18n::InvalidLocale
      # we do nothing when the locale is invalid, as this is a fallback anyways.
    end
  end
  false
end