Remove URL GET param for locale Rails 5

I have different languages in my app and I am using this pattern: /:locale/some-action. Most of my routes are in this scope :locale - routes.rb:

scope "(:locale)", locale: /fr|en/ do
  root to: 'home#index'
  get 'contacts', to: 'contacts#index'
end
get 'about', to: 'about#index'

, but some of them are not. For routes which are in this scope :locale, if I use their names like contacts_path, Rails generates the route depends on the locale. If it is :fr, generated route will be /fr/contacts.

For routes which aren't in this scope. For the example about. If I use its name about_path and locale is :fr, the generated URL will be /about?locale=fr, but I don't want this.

What is the way to remove this GET parameter, but still using routes which are in scope :locale with their names and generated URLs depends on :locale ?