In the light of the High Court's decision in R (Khan) v Secretary of State for Justice [2020] 1 WLR 3932 this paper contends that a revised approach to the interpretation of Articles 5 and 7 of the European Convention on Human Rights is needed. The paper argues that the Article 5 ECHR right to liberty and security plays a developing, though overlooked, role in the context of regulating determinate prison sentences. English law's conclusion that Article 5 of the ECHR has little to offer in this context is wrong and needs to be reconsidered. Equally, a more generous interpretation of Article 7 of the ECHR is now required: an approach which reflects the reality of determinate sentences.