Critical infrastructure protection is prominently concerned with objects that appear as indispensable for the functioning of social and political life. However, the analysis of material objects in discussions of critical infrastructure protection has remained largely within the remit of managerial responses, which see matter as simply passive, a blank slate. In security studies, critical approaches have focused on social and cultural values, forms of life, technologies of risk or structures of neoliberal globalization. This article engages with the role of 'things' or of materiality for theories of securitization. Drawing on the materialist feminism of Karen Barad, it shows how critical infrastructure in Europe is neither an empty receptacle of discourse nor does it have 'essential' characteristics, but emerges out of material-discursive practices. Understanding the securitization of critical infrastructure protection as a process of materialization allows for a reconceptualization of how security matters and its effects.