This paper addresses stabilization problem of a class of fractional order chaotic systems with unknown parameters. A systematic step by step approach is explained to derive control results using adaptive backstepping strategy. The analytically obtained control structure, derived by blending systematic backstepping procedure with Mittag-Leffler stability results, helps in obtaining stability of strict feedback like class of uncertain fractional order chaotic systems. Thereafter, the methodology has been applied to an example system i.e. chaotic Chua's circuit to addressed class to show the application of results. Numerical simulation given at the end confirms the efficacy of the scheme presented here.