Short-chain perfluoroalkylethyl methacrylates copolymerized with vinyl chloride and/or vinylidene chloride, a C.sub.12-C.sub.22 alkyl(meth)acrylate and one or more thermally crosslinkable or isocyanate-reactive monomers are useful for oil-, water- and soil-repellent finishing of fibrous substrates under particularly mild conditions.