A system for determining a wheel slip λ of a wheel on a heavy-duty vehicle is provided. The system comprises at least two antenna elements separated by a distance, a first processing unit arranged to receive a radio signal via the at least two antenna elements, to correlate the received radio signals against each other and to determine a speed over ground of the vehicle based on the correlation of the received radio signals. The system also comprises a wheel speed sensor arranged to determine a rotational velocity of the wheel, and a second processing unit arranged to determine the wheel slip of the wheel based on the rotational velocity of the wheel and on the speed over ground of the vehicle.