There exists in France a long tradition of manuals which comment on the ‘correct’ usage of the French language, written by a series of authors known as the Remarqueurs, and commencing in 1647 with the publication of Claude Favre de Vaugelas’s Remarques sur la langue française. These seventeenth-century manuals can be seen as an early manifestation of the diffusion of the French standard language, and they have been studied in depth by scholars such as Wendy Ayres-Bennett (1987, 2004, 2018) and Philippe Caron (2004). Similar works continued to be produced from the eighteenth century on, but some texts evolved to become aimed not only at encouraging ‘good usage’ but, specifically, at eradicating any usages that showed the influence of regional varieties, commencing in 1766 with the publication of Desgrouais’ Les Gasconismes corrigés. However, these texts have received far less scholarly attention, in spite of the fact that they highlight the centralising force of standardisation, in a period well before the use of French had spread across France. This paper will examine the content and discourse of Les Gasconismes corrigés, including the types of usage either promoted as ‘correct’ or condemned as ‘incorrect’ and the metalanguage used to do so, to determine the role played by this work in the standardisation of French.