The present paper focuses on the speech of a rural Afro-Brazilian community called Cafundó, situated 150 km from São Paulo. In 1978, when linguistic data were collected, the community constituted approximately eighty individuals, descendants of two slave women who inherited their owners’ proprieties. According to earlier studies, when the inhabitants of Cafundó spoke in their supposed ‘African language,’ Cupópia, they used structures borrowed from Portuguese and a vocabulary of possible African origin. A lexical analysis shows that the etymologies match historical and demographical data, indicating that speakers of varieties of Kimbundu, Kikongo and Umbundu dominated in the community. Through a morphosyntactic analysis, specific features were found in the data, such as copula absence and variable agreement patterns. By showing that some of Cupópia’s specific grammatical features are not derived from the Portuguese spoken by the same speakers but are instead shared with more restructured varieties, this paper defends the hypothesis that this lexically driven in-group code is not simply a regional variety of Portuguese with a number of African-derived words.