Parameters of an actuation distance model are adapted for an exhaust turbocharger actuator. For this, in the stationary or quasi-stationary operating state of the internal combustion engine, a first actuator is activated in the exhaust tract. The parameters of the actuation distance model are adapted on the basis of a comparison of the actual and target values for a modified state variable at the turbine. The change brought about by activation of the first actuator is compensated by activation of a second actuator in the fresh air tract.