A surgical stapler includes a body portion and a tool assembly. The body portion includes a large diameter portion and a small diameter portion extending distally from the large diameter portion. The large diameter portion supports larger internal components of the device including a lockout assembly adapted to prevent refiring of the stapler to allow the diameter of the small diameter portion of the device to be minimized to facilitate passage of the small diameter portion of the stapler and the tool assembly through an 8 mm trocar.