A clasp for securing an upper to the outsole of an article of footwear is disclosed. The clasp includes first and second releasably interengaging parts, one of which is attached to the upper and the other to the outsole. The part attached to the outsole includes a body defining a recess adapted to slideably receive the part attached to the upper. The recess has an opening through which the part attached to the upper is adapted to extend. The body has a centerline extending through the axis of the recess and the midpoint of the opening. That part also includes a base with a bottom surface adapted to be situated adjacent the outsole. The body is attached to the base such that the centerline of the body forms an obtuse angle with plane of the bottom surface of the base. The base has a top surface that is inclined relative to the bottom base surface. The clasp also has a spring-loaded detent mounted on one of the clasp parts. The detent co-operates with a detent-receiving recess on the other one of the clasp parts to releasably retain the clasp parts in the fully engaged position.