jats:titleAbstract</jats:title> jats:pIt will be argued that the United Kingdom Supreme Court (UKSC) should be bound by certain restrictions on its ability to develop the substantive criminal law: (i) the UKSC’s decision must plausibly be part of an (albeit edited) continuing legal narrative, not a fresh ‘striking out’ in a new direction; (ii) the UKSC should not make decisions that permit the conviction of the defendant when this development could not reasonably have been predicted, ex ante; (iii) the UKSC should take account of the ‘mood music’ (if any) of Parliament, the government and the Law Commission when deciding whether to develop the criminal law in a particular manner; and (iv) the UKSC should bear in mind the practical and epistemic limitations inherent in criminal proceedings (even on appeal). Recent judgments of the UKSC display insufficient regard for these considerations. Attention will be given, specifically, to Jogee (on complicity) and Ivey (on dishonesty).</jats:p>