An end effector of a surgical stapler includes first and second jaw members and a buttress material. The first jaw member is moveable relative to the second jaw member. The first jaw member includes a contact surface, a first projection, and a catch. The catch includes first and second fingers distal of the first projection. The second finger is biased toward the contact surface. The buttress material defines a longitudinal axis. The buttress material is releasably secured to the first jaw member. The buttress material defines first, second, and third slots formed therein. The first projection of the first jaw member is received in the first slot of the buttress material. The first finger of the catch is received in the second slot of the buttress material.