Thermoplastic molding compositions comprising A) from 10 to 99% by weight of at least one thermoplastic polyamide, B) from 0.01 to 30% by weight of at least one highly branched or hyperbranched polyetheramine, C) from 0 to 70% by weight of further added materials, where the total of the percentages by weight of components A) to C) is 100%; the use of polyetheramines for improving the flowability and/or thermal stability of polyamides; and to the use of the molding compositions for the production of fibers, of foils, or of moldings of any type, and also to the resultant fibers, foils, or moldings.