A work machine comprising a main body and a cab riser. The cab riser includes a cab and a frame comprising a first plate to contact a second plate provided on the main body in a first position which the cab is uprightly positioned on the work machine. The first and the second plate are coupled together to sandwich a key plate in the first position, the key plate being disposed in a space created by a first recess on a lower surface of the first plate and a second recess on an upper surface of the second plate, the second recess being aligned with the first recess vertically in the first position, and the key plate includes a first contact surface as a slope surface and a top surface being adjacent to the slope surface in the cross sectional view of the key plate.