2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90685We correct a mistake in a result reported in [PRA 64, 062106 (2001)], where it is rightfully argued that initial correlations between a system and its environment may render the system reduced dynamics not completely positive. We prove how not only these initial correlations but also the specific joint dynamics does play a significant role in the question of the complete positivy of the reduced dynamics.2 pages, no figuresQuantum Physicstext