A method comprising the steps: a manually applied driver steering moment is detected; a requested superposition moment is detected; the driver steering and superposition moments are combined to form an intermediate moment from which an assistance moment is generated by means of a predefined, non-linear amplification function; starting from detected values of the driver steering and superposition moments, a modified superposition moment compensating for friction in the electric steering system at least in part is determined such that the amount of the modified superposition moment is larger than the amount of the superposition moment at least for some pairs of variates comprised of driver steering and superposition moments; the assistance and modified superposition moments are combined to form a motor moment from which a corresponding input signal for a servo motor is established; the servo motor is controlled with the established input signal to provide the motor moment.