So there I was on a SYD-DRW flight cruising along quite happily in the FL3xx range when all of a sudden I feel the call of nature.
My FO, being only a CPL, can't fly the ship by himself (according to the red tape) so we divert to BNE for me to avail myself of the facilities.
Do that often enough and the problem will be fixed sooner than you can say "It's all the fault of the regulator"