The paper addresses the question whether light verbs may participate in the so-called grammaticalization cline (i.e. main verb → light verb → auxiliary). In contrast to the opinion that there is no evidence for the diachronic change leading from light verb to auxiliary and that light verbs are in fact diachronically ‘inert’, I argue that the history of the periphrastic perfect in Vedic Old Indo-Aryan does indeed attest such a process, a suggestion which is in accordance with recent findings concerning some Modern Indo-Aryan compound verb constructions.