Asian language support with headless RPM install

I’ve found a couple of discussions where Asian languages are displayed as boxes rather than the correct characters and the resolution was to go into options and enable Asian languages, but I’m running a headless system alongside unoconv to generate PDFs and so a GUI-based fix doesn’t do me much good.

I’ve got the same issue with an old 4.4 install and a fresh 5.1.0.3 install, both installed via the RPM tarball offering. Any suggestions?