Aarklash : Legacy

I use a left-handed mouse with a right-handed button config (my middle finger of my left hand is the traditional 'left-click').

For some reason, it seems Aarklash sees my mouse as an actual left-handed mouse (Razer Deathadder Left-Handed Edition) and assigns the buttons properly for a left-handed mouse.

Is there an option somewhere to swap mouse buttons that I'm missing?

Thanks!