Nieuport produced a number of prototypes either contemporary to, or based on the Nieuport 27, including one with a 150 horsepower Hispano-Suiza 8 V-8 inline engine that may have been designated the Nieuport 26, another with an enlarged 2 spar lower wing and a third with a redesigned front fuselage with a further simplified cabane structure, and a Vickers mounted on the forward port longeron.