Abstract Chaplinski Yupik (also often referred to as Siberian Yupik), a critically endangered Eskimo language spoken on the Bering coast in the north-eastern Siberia, shows numerous traces of language contact with Chukchi. A striking example is Chaplinski Yupik personal names, a significant part of which have Chukchi origin. In this study Chaplinski Yupik names are analyzed based on the genealogies of Chaplinski Yupik people compiled in 1970–1980s. The article focuses on phonological and grammatical adaptation of Chukchi names in Chaplinski Yupik. The case of personal names clearly reflects the history of Chukchi-Yupik language contact in the area – from an asymmetrical contact situation (the knowledge of Chukchi was common among Yupik speakers but not vice versa) and regarding Chukchi as a more prestigious language to a gradual loss of Chukchi-Yupik bilingualism by the end of the 20th century.