— A new method is presented for controlling the lateral foot placement of a simple 3D compass biped model. The method is based on the fact that, in the limit cycle, the gait is time-reversal symmetric and that, after a disturbance, the degree of asymmetry is indicated by a single variable. This variable is used for feedback with a proportional controller. Simulation results show that the controller works very well for a large range of gaits, without any adaptation of the parameter values.