The current focus on risk-based approaches to the governance of technology poses new challenges to the combined effort of policymakers and experts since the current worlds of technology and governance are very different. We make use of two hegemonic perspectives in these worlds, i.e. the systems and the network perspective, to analyse the expected contributions from expertise and experts to policy-making about infrastructures. The first question we address is how these two perspectives shape the expectations of the contribution of experts and expertise to problemsolving and policy-making. Second, we explore how practitioners may deal with inevitable conflicting expectations. Based on documents and previous research and illustrated with examples of flood-defence projects from the Netherlands, this paper concludes that perspectives may be coupled or uncoupled in practices of collaboration, and that practitioners should reconsider the contingent room to manoeuvre in policy-making, and the role they may take.