A corner fastener (10) is used for securing a first frame member (11) to a second frame member (12). The corner fastener (10) includes a body sized to be inserted in a cavity (11c)of the first frame member (11). Locking tabs (22 and 32) have first ends (22a and 32a) operatively connected to the body and second ends (22b and 32b) free to move between an unengaged position and an engaged position. The locking means have detent engaging members (24 and 34). The body has a fastening member aperture (27a and 37a). The aperture is in general axial alignment with an opening (12k), wherein when the body is positioned in the cavity and when a fastening member (50) is inserted in the opening and the aperture, the detent engaging member is locked in a detent by the fastening member, thereby fastening the first and second frame members together.