I revisit themes from Against Borders: Why the World Needs Free Movement of People (2020) in dialogue with Gillian Brock's Justice of People on the Move (2020) and Sarah Song's Immigration and Democracy (2019). We share the conviction that current border regimes are deeply unjust but differ in what migration justice requires. Brock and Song continue to give states significant discretion to exclude people from entering and settling in their territories, whereas I contend that migration justice demands open borders. I reject the claim that state self-determination justifies migration restrictions. Central arguments for open borders highlight the role that restrictive border controls and the state category of ‘immigrant’ play in upholding racialised hierarchies and exploitative economic relations, as well as in inflicting violence against mobile people.