message: Don't modify original options arg
diff: @@ -67,8 +67,7 @@ function safeCounterpartTranslate(text, options) {
  if (translated === undefined && count !== undefined) {
  // counterpart does not do fallback if no pluralisation exists
  // in the preferred language, so do it here
  - options.locale = 'en';
  - translated = counterpart.translate(text, options);
  + translated = counterpart.translate(text, Object.assign({}, options, {locale: 'en'}));
  }
  return translated;
  }
  