International audienceThis article analyzes some unintended consequences of the introduction of Scots, Scotland's nonstandardized vernacular, in a primary school. I show that the lack of established definition of the language or standardization entails three different processes: first, indexical links are established between Scots and a number of social properties (amusement, lack of seriousness); second, the pupils are othered in a process that constructs them as speakers of Scots; third, that process is completed by the reversal of this latter proposition: what the children speak is Scots (and not English) because of their geographic (and covertly social) origin, locking them in an identity as speakers of nonstandard/substandard language. This analysis allows me to discuss this case in terms of circulation of linguistic authority within the classroom in view of the indeterminacy of a legitimate or generally accepted version of Scots. I conclude by reflecting upon the nature of standard languages, whose status positions them not as just another linguistic variety on a par with others, but as forms of speech whose legitimacy lies not (only) within speakers' identity but within representative institutions, hence their claim to neutrality and inclusiveness, however sub-verted this may be in reality. [nonstandard, education, Scotland, linguistic authority, legitimate speaker