Introduction: With a definition that is evolving, a serious component of the contract cheating issue involves individuals paying a third-party to complete assessment items for them and then submitting this work as if it were their own. The issue of contract cheating poses a significant problem for tertiary institutions. The research literature conducted to date has addressed contract cheating, yet few papers discuss theory-based prevention strategies, and even fewer still evaluate the impact of theory-based prevention strategies. Case description: This paper discusses a case study of contract cheating that was identified in a business simulation operating in a capstone unit at a large Australian university. The problem is outlined, the theory-based intervention is explained, and the impact on the contract cheating problem is quantified. Discussion and evaluation: Building on a platform provided by criminological theory and crime prevention practice, the Unit Coordinator systematically adjusted a large number of assessment elements to ensure contract cheating was less likely. Importantly, this intervention was effective but also did not disadvantage students who were not engaging in contract cheating. Conclusions: Overall, this paper connects criminological theory and crime/problem prevention practice with academic misconduct issues with the intent of demonstrating there is potential to minimise the opportunity for contract cheating by altering the opportunity structures for assessment items. Crucially, this can be done without impeding genuine student efforts and does not depend on apprehension and conviction.