A locking device for locking a displaceable motor vehicle part which is lockable by the means of the locking device within a displacement range in a respective rest position reached by displacement is provided. The locking device comprising a braking device with at least two braking elements which interacts in a braking manner in a respective rest position of the motor vehicle part in order to lock the motor vehicle part. An actuator is assigned to the locking device, which is optionally combinable with the braking device and with which a displacement movement of the motor vehicle part is brakable for locking the motor vehicle part. The actuator is operatively connected independently on the braking device with a component which can be moved by displacement of a motor vehicle part so that a displacement movement of the displaceable motor vehicle part is brakable by the action of an actuator on the component.