A planar pressure bulkhead for an air- or spacecraft, including a first planar wall designed as a pressure seal for a fuselage structure, a second planar wall arranged opposite the first wall, and a reinforcing structure which is arranged between the first and the second wall and which includes at least one circumferential monolithic reinforcing element. Furthermore, the present disclosure provides an air- or spacecraft, including a fuselage structure and a planar pressure bulkhead that is coupled to the fuselage structure in a circumferentially continuous manner.