A process of making a reinforced hollow fiber membrane comprises flowing a membrane dope through a casting head while drawing one or more yarns or tows of filaments through the casting head. The filaments are spread apart in the casting head, for example by forcing the yarns or tows around a bend or through a narrow gap in the casting head. The filaments are adapted to bond to the membrane dope or the membrane wall. A reinforced hollow fiber membrane comprises a plurality of filaments individually surrounded by, and bonded to, the membrane wall.