I was able to workaround it by setting my screen size with xrandr. By default it got bogus values: (II) RADEONHD(0): Setting screen physical size to 1 x 257 ...which resulted in some super bogusness: resolution: 32512x101 dots per inch After xrandr --fbmm 300x230 all is in order again :-). Yielding to: resolution: 108x113 dots per inch -- i.