Although William Carleton’s literary dialect is regarded as reliably accurate, early in his career, Carleton practiced ‘dialect hygiene’. Carleton began this practice between the first two stories of Traits and stories of the Irish peasantry (1830). Scots-derived features of Ulster English and speech forms widespread in (non)standard varieties beyond Ireland were excised; forms shared by Ulster English and Southern Irish English were retained, and forms restricted geographically to Southern Irish English were retained or added. The result is a levelled peasant dialect that is intended to better reflect the speech of the majority of Irish people, which is arguably part of a strategy to make the language more national. Carleton’s practice reflects contemporary native-speaker attitudes to varieties of Irish English, which stigmatised Scottishness in speech. But dialect hygiene also served the political purposes of Carleton’s writing, for his primary objectives included the creation of an Irish national literature in English.