A wear member for attaching to a lip of an excavator wherein a boss is fixed to the lip has a front working portion; and a rear mounting portion adapted to overlie the boss when installed on the lip. The rear mounting portion includes a pair of legs, a first of the legs including an aperture, and a second of the legs including a rib extending toward the aperture. The aperture and the rib each define a bearing surface for engaging a lock to hold the wear member to the lip.