The invention therefore provides an additive for improving the cold flow performance of middle distillates, comprising I) at least one paraffin dispersant which is a derivative of a fatty amine, II) at least one block copolymer of the structure (AB)nA or (AB)m, where A represents blocks which are composed of olefinically unsaturated, aromatic monomers, and B represents blocks which are composed of structural elements based on polyolefins and are capable of cocrystallizing with the paraffins precipitating out of the middle distillate in the course of cooling, and n is a number in the range from 1 to 10 and m is a number in the range from 2 to 10.