The measurement of wellbeing is among the central aims of the capability approach. I develop one particular challenge to the operationalizability of the approach in the context of wellbeing measurement. I argue that the capability approach is both committed to Individuation of Wellbeing—the view that the wellbeing contribution of different capabilities and functionings is person-dependent—as well as Rejection of Subjectivism—the view that wellbeing should not be conceptualized in terms of subjective judgments of preference-satisfaction or happiness. I argue that there is (...) a tension between these two commitments that cannot be resolved in a viable way. (shrink)