The tag is present in Lintian version 2.104.234. That is the most recent version we know about.
For licensing reasons packages from the non-free section are not built by the autobuilders by default, so this source-upload to "non-free" will result in the package never appearing in the archive.
Please either perform a regular binary upload or (after checking the
XS-Autobuild: yes into the header part of
debian/control and get the package added to the "autobuild" whitelist.
Refer to Debian Developer's Reference section 5.10.5 for details.