The last development of this aircraft was the D.3803, with Saurer YS-3 engine, and modified dorsal fuselage (with an all-round visibility canopy). The D.3803 was armed with three HS-404 cannon (one in the nose, two in the wings), plus up to bombs and rockets. Despite not having a powerful engine, the type reached at . The performance was impressive, but the last development of this 1935 fighter design had several shortcomings and was not entirely successful. Its development was halted as P-51D Mustangs became available.