The present invention provides a device and a method for changing over an electric machine from the regular operating mode into the open-circuit mode. In order to avoid excessive increases in voltage and associated adverse effects on the electric machine and the other components, in particular batteries, a further control phase is introduced between the end of the regular operating mode and the freewheeling mode, during which further control phase the voltage at the terminals of the electric machine is continuously adjusted from the voltage previously set in the regular operating mode to the expected open-circuit voltage of the electric machine.