How to set lang attribute on html element with Nuxt?

Source: Declaring language in HTML tag · Issue #388 · nuxt/nuxt.js

head supports a htmlAttrs property. It will map each key:value of the object as attribute:value

module.exports = {
  head: {
    htmlAttrs: {
      lang: 'en'
    }
  }
}

How to do this when using i18n: Setting the language attribute when using i18n and Nuxt?