A surgical instrument is disclosed. The surgical instrument includes a handle portion, a channel, an anvil, and staple cartridge, a wedge member, a reciprocating firing device, and a lockout arm. The handle portion is operably configured to produce a firing motion and is coupled to the channel portion. The staple cartridge is engaged by the channel and includes a plurality of staple drivers to cam the staples toward the anvil, which is pivotally attached to the channel. The wedge member is proximal to and longitudinally aligned with the staple drivers, and the reciprocating firing device is responsive to the firing motion to progressively drive the wedge member from an unfired to a fired position. The lockout arm is pivotally attached to the channel and operably configured to pivot between a locked position and an unlocked position with respect to the firing device based upon a position of the wedge member.
