A surgical stapling device comprising: an adaptor assembly having a proximal end portion and a distal end portion; and a reload assembly supported on the distal end portion of the adaptor assembly, the reload assembly including: a shell housing including an outer housing portion and an inner housing portion, the inner and outer housing portions defining an annular cavity; a staple cartridge supporting a plurality of staples; a staple pusher supported within the annular cavity and movable from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge; a staple actuator supported within the annular cavity and movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position; a knife carrier supported within a through bore defined by the staple pusher and staple actuator and movable between a retracted position and an advanced position, the knife carrier supporting a knife; and a locking member slidably supported on the knife carrier, wherein the knife carrier has a proximal portion defining a circumferential groove, characterised in that the locking member is configured to be anchored against the circumferential groove and engage the staple actuator such that when the staple actuator is in its advanced position and the knife carrier is in its retracted position, the locking member inhibits re-advancement of the knife carrier. an adaptor assembly having a proximal end portion and a distal end portion; and a reload assembly supported on the distal end portion of the adaptor assembly, the reload assembly including: a shell housing including an outer housing portion and an inner housing portion, the inner and outer housing portions defining an annular cavity; a staple cartridge supporting a plurality of staples; a staple pusher supported within the annular cavity and movable from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge; a staple actuator supported within the annular cavity and movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position; a knife carrier supported within a through bore defined by the staple pusher and staple actuator and movable between a retracted position and an advanced position, the knife carrier supporting a knife; and a locking member slidably supported on the knife carrier, a shell housing including an outer housing portion and an inner housing portion, the inner and outer housing portions defining an annular cavity; a staple cartridge supporting a plurality of staples; a staple pusher supported within the annular cavity and movable from a retracted position to an advanced position to eject the plurality of staples from the staple cartridge; a staple actuator supported within the annular cavity and movable from a retracted position to an advanced position to move the staple pusher from its retracted position to its advanced position; a knife carrier supported within a through bore defined by the staple pusher and staple actuator and movable between a retracted position and an advanced position, the knife carrier supporting a knife; and a locking member slidably supported on the knife carrier, wherein the knife carrier has a proximal portion defining a circumferential groove, characterised in that the locking member is configured to be anchored against the circumferential groove and engage the staple actuator such that when the staple actuator is in its advanced position and the knife carrier is in its retracted position, the locking member inhibits re-advancement of the knife carrier.