Legend of Grimrock text unreadable on 4k screen

I just installed GOG LoG on Linux, and it looks like the fonts don't scale with the resolution. Are there any mods, replacement fonts or hidden settings to be able to read the text on a high resolution monitor?

I'm using the Nvidia proprietary graphics drivers, in case there are any tricks. As far as I can tell none of the options in the custom application profiles are relevant.

So far I've searched the official forums, Steam forums, GOG troubleshooting guide, [install directory]/game/README.linux and ~/.local/share/Almost\ Human/Legend\ of\ Grimrock/grimrock.cfg.

(Changing the screen resolution is a possibility, but definitely a last resort.)