It was lately argued, in Issue 242 of IJSL, that the Bildt dialect, spoken in Friesland from the 16th century on, is a specimen of so-called “mixed languages”, featured by a split between the source language of the “grammar” (from Frisian) and that of the “lexicon” (from Dutch). This paper assesses the linguistic arguments and offers a quite distinct conclusion to that above. Many of the grammatical resemblances between Frisian and the Bildt dialect are not the outcome of borrowing or imposition from Frisian, but are (a) shared innovations in Frisian and Dutch based varieties in Friesland (covering the Bildt dialect) in the 18th and 19th century, (b) commonly retained archaisms, and (c) the outcome of the convergence of Frisian with Dutch. It is proposed that all early-modern language varieties spoken in Friesland were part of a Sprachbund, that also covered the vernaculars of North Holland, under the umbrella of the emerging Standard Dutch. This distinct linguistic explanation makes the sociolinguistic argument of identity-driven language mixing outdated, as such a mixing never occurred. It can, however, be recognized that the actual shape of some Dutch-based varieties in Friesland can synchronically be re-assayed in terms of being “mixed languages”.