In this Reply, we discuss the relative stability of different forms of C i C s complexes. Based on the extended sections of IR absorption spectra reported by Lavrov [Lavrov2018] in his Comment, we identify that the C form is stabilized transiently in FZ-silicon during and just after electron irradiation. For longer time at room temperature, the C form disappears at the expense of the B form. Nonetheless, the C form, was found to be stable up to 280°C in Cz-silicon after neutron irradiation [Sgourou2013]. We attribute this apparent discrepancy to a vacancy-induced C i C s dissolution mechanism that drives the electron irradiated sample in a non-equilibrium state that differs from the equilibrium state predicted by DFT calculations [Timerkaeva2018]. In the neutron irradiation experiment, the generated vacancies are trapped by oxygen interstitial allowing the thermodynamics equilibrium to be preserved.