A parking assistance system is provided for a motor vehicle, with a sensor device which is configured to measure a distance of the motor vehicle from an object and an intrinsic speed of the motor vehicle, with a warning device, which is configured to compare the measured distance with a distance threshold value and to output a warning signal if the measured distance drops below the distance threshold value. The warning device is configured to adapt the distance threshold value taking the measured intrinsic speed into account. Furthermore, a method is provided for operating a parking assistance system, a computer program, a computer-readable medium and a motor vehicle.