A method for re-tensioning an automatic parking brake by an electric motor includes carrying out a re-tensioning process after a predefined time period after the tensioning of the parking brake. The parking brake is driven in the tensioning direction by the electric motor to determine the travel carried out by the parking brake in the tensioning direction and the clamping force exerted by the parking brake during the re-tensioning. The method further includes carrying out a further re-tensioning process after a predefined time if the travel of the parking brake is less than a predefined threshold value and the clamping force in the parking brake is less than a second threshold value. If the travel of the parking brake is greater than a third threshold value or the clamping force exerted by the parking brake is greater than a fourth threshold value, a further re-tensioning process is not carried out.