The supply of the 13.2 mm guns was clearly limited, and in a further attempt to increase the firepower of the design the Romanians signed a deal with Ikaria in Germany for a supply of 20 mm MG FF/M cannon. These were a licensed version of the Swiss Oerlikon FF, which had been in use in various German aircraft. The new gun also required a redesign of the wing. The 60 IAR 81Bs were intended to be dive bombers, but were delivered as IAR 80Cs fighters (a designation that appears painted on the tail of this model) without the centerline bomb rack. After the first 10 were completed, self-sealing tanks were added along with improved seat-back armor. The first 10 were delivered in December 1942 and the entire order was completed by April 1943.