In 2019, Thailand ratified the International Labour Organization Work in Fishing Convention to protect migrant fishers. The Thai government vigorously promoted the Convention among its constituents. Yet, despite the government’s proactivity, such norms have been weakened upon local translation. This phenomenon is not readily explained by existing norms research that pays scant attention to norms in the domestic space. To address this oversight, this article unpacks domestic processes of norm validation and makes a two-step argument. First, it argues that norm validation is crucial for instigating domestic implementation by allowing stakeholders to deliberate and contest the ‘appropriate’ application of norms. Second, it argues that the locally acquired normative understanding, as influenced by norm antipreneurs, or actors who defend the status quo, weakens norm implementation while the norms’ discursive strength is retained. In presenting the findings, this article contributes to the norms literature by illuminating a new life given to validated norms. The contribution also interrogates norms’ global–local dynamics by scrutinizing norm contestation and the extent to which it generates an internalized sense of legal obligation to implement international norms.