A device for driving an auxiliary unit, in particular a high-pressure pump is provided. The device includes a rotatably supported drive shaft of an internal combustion engine coupled to a unit shaft of the auxiliary unit by a coupling. The unit shaft has a first bearing on the side facing away from the coupling, and a second bearing formed by the coupling. The device provides a coupling solution for connecting, for example, a high-pressure pump camshaft to an available intake or exhaust camshaft.