Justin’s epitome is a central source for significant parts of especially Hellenistic history, and it is our only window into the important work of Trogus. To understand Justin’s epitome and use it methodologically soundly, a reasonably firm grasp on its date of composition is, as always with ancient writers, central. This has proved elusive: the only indisputable terminus ante quem is Jerome’s mention of Justin from 407, and most commonly Justin is dated to either the year 200 or the late fourth and early fifth centuries. This article provides new arguments for a late dating of Justin’s work: Justin presents the obeisance demanded by Alexander the Great as a form of adoratio, a gesture which in turn is depicted as royal and Persian. This presentation of Alexander’s obeisance deviates markedly from the parallel sources, and the conceptualization of adoratio as Persian is unprecedented before the fourth century. On the other hand, Justin’s description exhibits clear parallels with the fourth-century critique of Diocletian for introducing the adoratio. This provides strong support for a late dating of Justin’s work, and the 390s or the first years of the fifth century may tentatively be suggested.