A parking brake for a vehicle, including a parking brake unit, an actuating device situated inside the vehicle and operable to transmit an actuation signal to a control unit, a hydraulic circuit of a service brake of the vehicle connected to the parking brake unit, and an actuator and locking device for locking the parking brake in a braking position; the parking brake is actuatable by means of the hydraulic circuit and the actuator is a brake booster of the service brake.