Hugo. Is there a way to generate a valid URL from asciidoc link:file.adoc[title]

I have a hugo project structure like this:

content/
   _index.md
   a.adoc
   b.adoc

There is a cross-reference to the a.doc in b.adoc

link:a.adoc[The page "a"]

Hugo renders the link to the URL like this: http://my-site.com/a.doc

But this page doesn't exist and i get 404 when going to the URL. The valid URL is http://my-site.com/a

Is there a way for generating a valid URL like above? There may be a solution similar to markdown-render-hooks?

layout
  _default
    _markup
       render-link.html