A technique is described for the redundant registering of an actuation of a motor-vehicle brake system. A device which is provided for this purpose comprises a first sensor for generating a first sensor signal which indicates a movement of a mechanical input component of the brake system, and a second sensor for generating a second sensor signal which indicates a hydraulic pressure in the brake system. A processing device which is coupled to the two sensors is configured for selectively outputting an actuation signal which is generated on the basis of the first sensor signal or an actuation signal which is generated on the basis of the second sensor signal. The actuation signal indicates an actuation of the brake system.