A surgical stapling apparatus, comprising: a first jaw member having a locking assembly and defining a channel a cartridge configured to selectively couple to the first jaw member, the cartridge having fasteners and an actuator having a proximally extending finger a second jaw member having an anvil with staple forming depressions a drive member movable through the channel from a retracted to an advanced position to drive the fasteners toward the anvil, the drive member pushing a sled so that the sled interacts with a pusher the actuator being coupled to the sled and biased against the pusher, the finger of the actuator aligning with the locking assembly when the cartridge couples to first jaw member the locking assembly including a locking lever biased toward the channel of the first jaw member, the finger of the actuator contacting the locking lever when the cartridge is coupled to the first jaw, rotating the locking lever to a position away from the channel, the locking lever moving to a position blocking the channel when the drive member is moved to the advanced position.
