Vastly increased transnational business activity in recent decades has been accompanied by controversy over how to cope with its social and environmental impacts. The most prominent policy response thus far consists of international guidelines. We investigate to what extent and why citizens in a high-income country are willing to restrain companies for the sake of improving environmental and social conditions in other countries. Exploiting a referendum in Switzerland, we use choice and vignette experiments with a representative sample of voters (N=3010) to study public demand for such regulation. Our results show that citizens prefer strict and unilateral rules, while correctly assessing their consequences. Moreover, exposure to international norms increases demand for regulation. These findings highlight that democratic accountability can be a mechanism that motivates states to contribute to collective goods even if not in their economic interest, and that awareness of relevant international norms among citizens can enhance this mechanism.