A composition contains a polyester; an aromatic epoxy compound, in an amount sufficient to provide 5 to 300 milliequivalents of epoxy per kilogram of polyester; and 0.5 to 6 weight percent, based on the weight of the polyester, and an ethylene-glycidyl methacrylate containing copolymer; and/or a copolyester copolymer, wherein the copolyester comprises, based on the weight of the copolyester, 15 to 95 weight percent of polyester units derived from the reaction of a C6-C24 aromatic dicarboxylic acid or a chemical equivalent thereof with a C2-C6 aliphatic diol, and 5 to 85 weight percent of polyester units derived from the reaction of a C6-C24 aromatic dicarboxylic acid or a chemical equivalent thereof with a poly(alkylene oxide) glycol having a molecular weight of 400-6,000 and a carbon to oxygen ratio of 2.0-4.3. The compositions have excellent hydrolytic resistance, and are suitable for making automotive and electronic parts.