The effects of the addition of trace amounts (12-96 at PPM) of Sc upon the annealing of otherwise high-purity Cu quenched from 600-700 degrees C has been investigated. The Sc solute was observed to suppress the normal post-quench vacancy annealing in Cu, apparently by the formation of highly stable vacancy-Sc complexes which subsequently annealed only at temperatures in excess of approximately 300 degrees C.