A method for operating a device configured to provide a dosed supply of a liquid. The device has: a pump delivering the liquid and having a pump housing having an inlet and an outlet, an eccentric on the pump housing, and a deformable diaphragm arranged between the pump housing and the eccentric. The deformable diaphragm and the pump housing delimit a delivery path from the inlet to the outlet and form at least one seal of the delivery path, the seal being displaceable along the delivery path by a movement of the eccentric to deliver the liquid. The method comprises: detecting a demanded dose amount of the liquid; activating the pump to deliver the liquid by the pump; stopping operation of the pump when the delivered amount of the liquid corresponds to the demanded dose amount; deactivating the pump when the eccentric is situated in a predefined park position.