The invention relates to thermoplastic molded masses, comprising A) 10 to 97 wt. % of at least one thermoplastic polyester, B) 1 to 30 wt. % of a flame-resistant agent combination with, based on 100 wt. % B), b1) 20 to 99 wt. % of a halogenated flame resistant agent, b2) 1 to 80 wt. % of a antimony oxide, C) 0.01 to 3 wt. % of at least one polyamide, D) 0.01 to 2 wt. % of at least one nigrosin, E) 0.01 to 3 wt. % of at least one anti-dripping agent and F) 0 to 70 wt. % of further adjuncts, whereby the sum of components A) to F) is 100%.