A fixing plug for anchoring in an irregular hole in a substrate, the plug having an elongate body with an internal bore for receiving a screw, closure means adapted to close the opening of said hole, at least one opening in said closure means, and a plurality of support fingers extending radially outwardly from said body, said support fingers being resiliently detected by contact with walls of the hole on insertion of the plug into the hole, the fingers sensing to hold the plug substantially centrally within the hole.