Ethnographies often show that users appropriate and adapt technology in ways never envisaged by the designers, or even deliberately subverting the designers’ intentions. As design can never be complete, such appropriation is regarded as an important and positive phenomenon. However designing for appropriation is often seen as an oxymoron; it appears impossible to design for the unexpected. In this paper we present some guidelines for appropriation based on our own experience and published literature and demonstrate their use in two case studies. You may not be able to design for the unexpected, but you can design to allow the unexpected.