Why does Windows show restricted WebDAV directories?

Question

I am using apache as my WebDAV server to share some files for users. They all have their own directory in a global /users directory. Thus, a script configures the dav config to be something like that:

<Directory /var/lib/dav/data/users/user-1>
  Dav On
  Options Indexes FollowSymLinks
  AuthType Digest
  AuthName "WebDAV"
  AuthUserFile "/user.passwd"
  <RequireAny>
    Require user webdav-admin user-1
  </RequireAny>
</Directory>

<Directory /var/lib/dav/data/users/user-2>
  Dav On
  Options Indexes FollowSymLinks
  AuthType Digest
  AuthName "WebDAV"
  AuthUserFile "/user.passwd"
  <RequireAny>
    Require user webdav-admin user-2
  </RequireAny>
</Directory>

This configuration works fine in the Web browser, where users see only their own directory in the /users directory.

If I connect using Windows, however, the user sees

|-users
  |- user-1
  |- user-2

They may not see the content of the subdirectories tho.

How can I prevent them from seeing other user's names?

Disabling indexes is not an option, since the users should still be able to browse freely - just their own directories though.

Thanks in advance.