After production ended, efforts were made to improve the armament to keep the vehicle relevant on the battlefield. Attempts were also made in 1933 to mount a 37 mm tank gun in the hull of the vehicle to give it "anti-tank capabilities". It was determined to be "impractical" and therefore abandoned. The Type 98 20 mm machine cannon was successfully mounted on the hull of a number of the vehicles after 1937, in place of the 13.2 mm machine gun. In addition, an external anti-aircraft mount was stowed in the vehicle, which could be attached to the outer rear facing of the turret, allowing an additional Type 91 machine gun to be mounted. The engine hatches could be opened and locked together to form a seat for the gunner using the externally mounted machine gun.