In this paper, on a talk given at Lawrence Berkeley Laboratory, we discuss higher-order non-perturbative corrections in inclusive semileptonic decays of B mesons. First the generic calculation is reviewed and then we identify the relevant hadronic matrix-elements up to [Formula: see text]. For a quantitative analysis of these effects, the value of these new matrix-elements is estimated within an approximation scheme. We investigate the role of so-called "intrinsic-charm" operators in this decay, appearing first at order [Formula: see text] in the heavy-quark expansion. These operators induce an expansion infrared sensitive to the charm quark [Formula: see text]. Parametrically the power corrections complement the estimate of the potential impact of [Formula: see text] contributions, which we will explore. In this context, we draw semiquantitative conclusions for the expected scale of valence weak annihilation contribution in semileptonic B decays. Furthermore the effects on the integrated rate and on kinematic moments are then estimated up to [Formula: see text].