Thermoplastic polyester molding compositions with improved heat distortion point contain, per 100 parts of a linear saturated polyester, from 1 to 100 parts of a rubbery graft copolymer, from 10 to 100 parts of an .alpha.-methylstyrene/acrylonitrile copolymer, and from 0 up to 80, preferably 10 to 80 parts of a filler, especially glass fibers as the filler. They can be converted to shaped articles by extrusion or injection molding.