A new consent-based sexual crimes legislation came into force in Finland in January 2023. Under the new legislation, rape is defined as sexual intercourse with a person who does not participate voluntarily (Chapter 20 s 1 of the Criminal Code). A person is not participating voluntarily if they have not expressed voluntariness through words, actions, or another manner (‘yes means yes’) or, even if voluntariness has ostensibly been expressed, if the perpetrator carries out the sexual intercourse using violence or a threat, or by abusing the other’s inability to formulate or express their will. This paper is an exploration of the limits of the new definition using example cases drawn from court cases, legal literature, and stories reported in the media, from Finland and abroad. The first part examines the definitions of voluntariness and sexual self-determination. Voluntary participation requires making a choice and possessing the capability, freedom, opportunity, and overall possibility for making that choice. I suggest that both voluntariness and sexual self-determination should be understood as relational qualities whose evaluation should be sensitive to context. The second part examines the operation of the voluntariness criterion in example cases, covering severe intoxication, being half-asleep, conditional consent, stealthing, sexual fraud, error in motivation, pressuring, and the abuse of a position of power. Different limits of the new consent-based definition of rape are encountered in these examples.