We consider the instanton contributions for the production of a gluon jet with large transverse momentum in QCD. We find that Mueller's corrections corresponding to the rescattering of hard quanta are likely to remove the contributions of large instantons, making this cross section well defined. This observation generalizes the previous discussion of instanton effects in deep inelastic scattering and suggests that all hard processes in QCD receive hard non-perturbative corrections from instantons of small size, of order p not, vert, similar 1/(Qαs).