We calculate the radiative corrections to the nonleptonic inclusive B decay mode taking into account the charm quark mass. Compared to the massless case, corrections resulting from a nonvanishing c quark mass increase the nonleptonic rate by (4--8), depending on the renormalization point. As a by--product of our calculation, we obtain an analytic expression for the radiative correction to the semileptonic decay taking into account the lepton mass, and estimate the c quark mass effects on the nonleptonic decay mode .