The activation energy for migration of a divacancy in copper has been : alculated to be 0.47 eV in a pure copper lattice and 0.74 eV if the divacancy contains a helium atom. The result for the pure divacancy is in reasonable agreement with reported experimental values. The energy required for a helium atom to migrate from one vacancy to the other in a divacancy is found to be 0.18 eV so that the rate-limiting step in the migration of helium in copper via a divacancy mechanism is the movement of the divacancy at 0.74 eV.