This article concerns identity work—both the semiotic processes through which it is accomplished and the motivation behind it. Specifically, this article focuses on ethnolinguistic identity: how ethnolinguistic grouping is sustained by linguistic ideologies and how rigid categorization is toned down in everyday practice. Using an empirical study of the relations of sameness and distinction established with the Siwan group by non-members through their use—or non-use—of the Siwi language, this article will attempt to show that, based on Siwi's acquired status as an icon of group identity, the language is used as a resource for identity work by non-members to express their position vis-à-vis the Siwan group. •Ethnolinguistic grouping is sustained by essentialist ideologies.•Portrayed as central to ‘Siwanness’, Siwi becomes an icon of group identity.•Ethnic Siwi is exploited as a way to identify with the ethnolinguistic Siwan group.•Identity inheres in actions—it is fluid and circumstantial.•Analysing situated language–identity relations enriches minority languages studies.