Require one of the pilots to have his hands on the controls during the approach, monitor the flight path / flight instruments and override / disconnect the automatic stuff if it does not perform as expected
Where does all this end? Why not have both pilots with hands and feet on the controls in case one suffers a subtle incapacitation. And if there is a spare pilot in the jump seat he could be given the task of monitoring both pilots in order to be the first to detect the first signs of a heart attack, or epileptic fit.
