The Renault R40 was an improved design based on the Renault R35 although it is sometimes considered a variant of the R35. The R40 served in the Battle of France in 1940 but only in small numbers as production was halted in May 1940. Exact numbers are unknown but at least 130 hulls were built although not all were fitted with turrets and sent into service. The R40 was armed with the same 37mm L/21 SA18 gun as the R35.