1. Thermoplastic molding composition comprising A) from 30 to 99.99% by weight of a polyester composed of from 50 to 100% by weight of at least one polyalkylene terephthalate A1), based on A), and from 0 to 50% by weight of a polyester A2), differing from A1), B) from 0.01 to 2% by weight of an acrylic acid polymer, composed of B1) from 70 to 100% by weight of acrylic acid, B2) from 0 to 30% by weight of at least one other ethylenically unsaturated monomer copolymerizable with acrylic acid, selected from the group of monoethylenically unsaturated carboxylic acids, and C) from 0 to 70% by weight of other additional substances, where the total of the percentages by weight of components A) to C) is 100%.