Inspired by: https://gitlab.gnome.org/GNOME/gnome-characters/commit/36a2e4f8a7c42447f40a797005ddeae0255151d0#0cc1139e3347f573ae1feee5b73dbc8a8a21fcfa_0_14
Fixes build on Gentoo.
Signed-off-by: David Heidelberg david@ixit.cz