A method for operating a device for injecting water into an internal combustion engine, the device including a water tank for storing water, a pump for conveying the water, the pump being connected to the water tank via a first line, and the pump being operable in a conveying mode and in a back-suction mode, a drive for driving the pump, at least one water injector, which is configured to inject water into an air-conducting line of the internal combustion engine, the water injector being connected to the pump via a second line, the at least one water injector being opened during the operation of the pump in the back-suction mode, in which the water is conveyed in the direction of the water tank, so that air flows into the second line.