A linear surgical stapler adapted for applying a plurality of surgical fasteners to body tissue includes an anvil structure and a cartridge housing containing a plurality of surgical fasteners. The cartridge housing and anvil structure are relatively movable between a first spaced apart position and a second position in close approximation with one another. A firing mechanism is associated with the cartridge housing for ejecting the surgical fasteners from the cartridge housing to be driven against the anvil structure. A lockout mechanism interacts with the cartridge housing for selective activation and deactivation. The lockout mechanism includes a swing gate tab secured to the cartridge housing at a position adjacent a lockout lever, such that firing of the linear surgical stapler rotates the swing gate tab releasing the lockout lever for preventing further firing of the used cartridge housing.