Though attention to evaluating human-robot interfaces has increased in recent years, there are relatively few reports of using evaluation tools during the development of human-robot interaction (HRI) systems to improve their designs. Heuristic evaluation is a technique suitable for such applications that has become popular in the human-computer interaction (HCI) community. However, it requires usability heuristics applicable to the system environment. This work contributes a set of heuristics appropriate for use with HRI systems, derived from a variety of sources both in and out of the HRI field. Evaluators have successfully used the heuristics on an HRI system, demonstrating their utility against standard measures of heuristic effectiveness.