Safety circuit for a rotary drive, in particular for a vehicle hatch, which circuit has a braking effect on the rotary drive when the rotary drive is deactivated and external forces are applied to the hatch from the outside, the rotary drive comprising at least one electric motor, the winding of which can be short-circuited by at least one triac, in which just one triac is provided between the connections of the winding, the gate of which triac is connected to one of the connections by two Zener diodes that are connected in series in an anti-parallel manner.