A forceps includes an end effector assembly having first and second jaw members, each jaw member including a tissue sealing plate disposed thereon. One or both of the jaw members is movable relative to the other between a spaced-apart position and an approximated position for grasping tissue therebetween. One or both of the jaw members defines a first channel extending therethrough and an opening in the tissue sealing plate thereof that is aligned with the first channel. A stop member having a pre-determined configuration is removably engaged within the first channel. At least a portion of the stop member is configured to extend through the opening of the tissue sealing plate to define a minimum gap distance between the tissue sealing plates of the jaw members when the jaw members are disposed in the approximated position.