The paper examines an ancient superstition evoked in Servius’ commentary (Serv. ad Aen. 6, 284); Servius mentions that, according to a certain authority on dreams, visions seen in the autumn months are particularly untrustworthy. The first part of the article reviews other references to this popular belief (Plut. Quaest. conv. 8, 10, 734d–736b; Alciphr. Ep. 2, 2; Basil. Ep. 207, 1). The second part attempts to reconstruct the reasoning of the authority that Servius had used (qui de somniis scripserunt) and at the same time to distinguish Servius’ own view on the matter. It is shown that, although the remark on the unreliability of autumn dreams in itself is of little pertinence to the understanding of Virgil’s text, it is part of a larger, fairly elaborate exegetical tradition that sought to establish a connection between Aen. 6, 282–284 and 6, 893–898.