Abstract: Door reinforcing apparatus (2) comprising a lock guard (4) for fitting to an outer face (10) of a door (12) adjacent a lock (14) in the door (12), and fixing studs (18) for fixing the lock guard (4) in position, the lock guard (4) being larger than the lock (14), the lock guard (4) having a side wall (20) which extends over the outer face (10) of the door (12) and an end wall (22) which abuts the edge (24) of the door (12) during use of the door reinforcing apparatus (2), the side wall (20) having a key aperture (26) for receiving a key for the lock (14), the end wall (22) having a lock aperture (30) for receiving at least a bolt part of the lock (14) so that the bolt part of the lock (14) can pass backwards and forwards through the lock aperture (30 ) during operation of the lock (14), and the fixing studs (18) comprising studs (40) which extend from an inner face (42) of the side wall (20) of the lock guard (4) parallel to but spaced apart from the end wall (22), and screw members (44) which pass through ap