This paper tracks the diachronic evolution of Mauritian’s future markers pour and va. It is commonly assumed that pour denotes a definite future, whilst va expresses an indefinite one. However, there is little consensus as to what ‘indefinite’ means. This concept is quantified and clarified by establishing characteristic features that constitute a canonical ‘indefinite’ future, following Corbett’s canonical typology approach (2007). Contrary to the hypothesis that pour and va would follow previously identified grammaticalisation paths, my data show an unexpected late development of a new ‘obligation’ meaning for some speakers.