Musannaf Ibn Abi Shayba 3:1277

Abu Usama narrated to us, from Mufaddal ibn Muhalhal, from Mughira, from Ibrahim, who said: They used to consider it recommended for the one who was preceded by some of the prayer in Fajr, Maghrib, or Isha, when he stands to make up [the missed portion], that he should recite aloud, so that he who does not know may know that the recitation is [to be done aloud] in what he is making up.