A commonly invoked procedure for calculating steady state nucleation rates employs a chemical kinetics argument in which the rate constants are assumed to be the same as in a so-called “constrained” equilibrium state of the system of interest. Such a procedure implicitly ignores the possibility that in some nonequilibrium nucleation processes spatial correlations among the reactants can cause the relevant rate constants to be different from their equilibrium values. Void nucleation is an example of a situation in which this phenomenon occurs. We show how to modify the usual theory to account for the local depletion of vacancies in the vicinity of a forming void. A numerical example illustrates the conclusion that the local depletion effect produces nucleation rates which can be very much smaller than those predicted by models in which there is complete spatial uniformity.