Large companies are accustomed to building strong relationships with their suppliers, leveraging close collaboration for innovation and co-development agreements. However, when a web-based platform is implemented for sharing data and managing innovation projects, suppliers, who have access to sensitive information through these partnerships, can exploit loopholes in these collaborations. This case study describes the opportunistic behaviour of suppliers and related threats faced by large companies when dealing with open innovation systems. We examine how procurement needs to design or adapt a supplier relationship strategy for open innovation, to avoid opportunistic behaviour that could result in a loss of competitive edge.