The invention relates to a method for regulating the mixture in an internal combustion engine by means of a catalytic converter and a lambda probe that is placed downstream of the catalytic converter. Depending on the historical signal values, said method determines whether intervention in the formation of the mixture is required, whether the existing signal is only decreasing slowly, which necessitates slow regulatory intervention, or whether the signal of the probe placed downstream of the catalytic converter decreases rapidly, which necessitates rapid regulatory intervention. The difference types of intervention enable the volume of the catalytic converter to be reduced, thus preventing high consumption in the warm-up phase or the poor start-up behavior of large catalytic converters.