This chapter questions the Canadian border’s reconstitution as a site of punishment for refugee claimants by examining the Designated Foreign National (DFN) regime, which permits the Canadian government to discipline foreign nationals for suspected violations of Canadian border laws by subjecting them to penalties that are formally classified as administrative, but amount to de facto punishment. These include mandatory arrest and detention, as well as compulsory reporting and ongoing document inspection. In this chapter, I examine the operation of the DFN regime in relation to other border measures, focusing specifically on the Canada-US Safe Third Country Agreement. I argue that the Agreement not only closes the Canadian border to refugees, it also reconstitutes those claimants through discourses of criminality and illegality, and thus plays a key role in producing the very ‘irregularity’ that the DFN regime is designed to punish. Proceeding from this claim, I argue that the DFN regime is premised on a legal and conceptual flaw: it presumes ‘irregularity’ to be an essential subject position that reflects a transgression of Canadian border laws when, in fact, it is a constitutive subject position produced by them. By punishing refugee claimants for this deemed irregularity, the DFN regime does more than enhance Canada’s ability to punish refugee claimants through arrest and detention. Instead, it introduces a far more extreme form of punishment into Canadian refugee law: it effectively empowers the government to punish refugee claimants for trying to avail themselves of the right to seek asylum in Canada.