A redundancy module for a pneumatic braking system of a vehicle, in particular a commercial vehicle, with spring brakes on at least one axle, includes: a parking brake pressure port for receiving a parking brake pressure; a spring brake port for providing a spring brake pressure; a redundancy pressure port for receiving a redundancy pressure; and a piston assembly, with a reverse piston having a parking brake pressure control surface, a spring brake control surface, and a redundancy pressure control surface. The parking brake pressure acting on the parking brake pressure control surface causes a control of the spring brake pressure in a same direction. The redundancy pressure acting on the redundancy pressure control surface causes an inverse control of the spring brake pressure.