A safety apparatus for a fifth wheel coupling having locking jaws arranged to detachably couple to a trailer having spring applied air brakes, the fifth wheel coupling comprising a locking component that is moveable between a first position whereat the locking jaws are in a coupled state and a second position whereat the locking jaws are in a decoupled state, the safety apparatus comprising a pneumatic valve arrangement pneumatically coupled to both a constant air pressure supply and an air park brake supply that supplies pressurised air to the spring applied air brakes, and a mechanical actuator mechanically coupled to the locking component and configured to mechanically actuate the pneumatic valve arrangement when the locking component moves from the first position to the second position, thereby causing the pneumatic valve arrangement to block flow in an air park brake supply line for preventing the spring applied air brakes from releasing.