jats:pThe role of manuscript corrections in studying textual transmission of the New Testament has been long recognised by textual critics. And yet, the actual witness of corrections may at times be difficult to interpret. A case in point is Josef Schmid's seminal work on the text of Revelation. Following Wilhelm Bousset, Schmid argued that a particular group of corrections in Codex Sinaiticus reflected a jats:italicVorlage</jats:italic> with a text akin to that of the Andreas text-type. By dating these corrections – unlike Bousset – to the scriptorium, Schmid utilised their witness to trace the text of Andreas back to the fourth century. Recently, Juan Hernández has shown that the corrections cited by Schmid were significantly later, hence calling his fourth-century dating of Andreas (among other things) into question. Through an analysis of the corrections cited by Schmid, supplemented by a fuller data-set of Sinaiticus’ corrections in Revelation, this study seeks to reappraise Schmid's claims concerning the textual relations of these corrections, and identify their role in the later transmission of the text of Revelation.</jats:p>