Abstract: Public-private partnerships (PPPs) are known as challenging contractual endeavors to public sector managers, and governments are developing standard contracts in order to ease the contracting process toward PPP deals. This study examines the learning process governments go through while managing the procurement trajectories of PPPs over time and revising the model contract they use, thereby gradually moving toward the formulation of a standard contract. It presents a case study of four consecutive road infrastructure projects in Belgium that looks into the contractual changes that were made over time and explains the reasons behind those changes. The results indicate a learning process that is characterized by an open attitude to learning of public sector actors, and a leading role of private sector actors-primarily financiers-in proposing or even requiring change. Contrary to theory-based expectations, the government continuously tested whether its model contract was in line with market practice, rather than increasingly limiting the room for negotiation as it gained experience.