Fuel cell stack housing including at least a bottom section and a first and a second side wall, which are spaced apart by the bottom section, wherein the housing is adapted to house a fuel cell stack and includes at least one fastening element, which is engaged with the first and the second side wall, wherein at least the first side wall of the housing has a flat section and an arched section extending in direction of the second side wall, and wherein a maximum possible distance between the arched section and the bottom portion defines an inner height of the fuel cell stack housing, where in the inner height of the fuel cell stack housing is adjustable, as well as a fuel cell stack assembly including a fuel cell stack encased by such a housing.