  We show that in a Wilsonian renormalization scheme with zero-momentum
subtraction point the massless Wess-Zumino model satisfies the
non-renormalization theorem; the finite renormalization of the superpotential
appearing in the usual non-zero momentum subtraction schemes is thus avoided.
We give an exact expression of the beta and gamma functions in terms of the
Wilsonian effective action; we prove the expected relation $\beta = 3g\gamma$.
We compute the beta function at the first two loops, finding agreement with
previous results.
