A method for operating a device for providing a liquid additive having at least one suction point for removing liquid additive from a tank, a valve-free conveying line extending from the suction point to a supply unit, and a valve-free displacement pump, the displacement pump being configured to convey the liquid additive from the tank via the suction point along the conveying line to the supply unit, the displacement unit having at least one seal of the conveying line, displaceable along the conveying line for conveying the liquid additive, includes: a) detecting a stoppage of operation of the device; b) establishing a position of the seal within the positive-displacement pump; and c) changing the position of the seal if the position of the seal does not correspond to a provided park position of the seal.