In this paper we propose an innovative way of dealing with the design of fault tolerant control systems. We show how the nonlinear output regulation theory can be successfully adopted in order to design a regulator able to offset the effect of all the possible faults which can occur and, so doing, also to detect and isolate the occurred fault. The regulator is designed by embedding the (possible nonlinear) internal model of the fault. This idea is then applied to the design of a fault tolerant controller for induction motors in presence of both electrical and mechanical faults.