This article presents the framework Capability Sensitive Design (CSD), which consists of merging the design methodology Value Sensitive Design (VSD) with Martha Nussbaum's capability theory. CSD aims to normatively assess technology design in general, and technology design for health and wellbeing in particular. Unique to CSD is its ability to account for human diversity and to counter (structural) injustices that manifest in technology design. The basic framework of CSD is demonstrated by applying it to the hypothetical design case of a therapy chatbot for mental health. By applying CSD to a design case, the merits of this new framework over the standard VSD approach become apparent. Also, the application demonstrates what a technology design would look like when attention is paid to capabilities right from the start of the design process.