Why do male legislators (sometimes) support gender quota laws? Existing literature has primarily focused on external factors such as party interests, international pressure, and advocacy by interest groups. We offer a complementary, yet overlooked, explanation centered on the career ambitions of individual legislators. We argue that in chambers where legislators anticipate shorter parliamentary tenures, a gender quota may not threaten men's mid- or long-term career prospects, making them less opposed to quota adoption. We develop a theoretical model linking legislators' career expectations to their incentives to block or delay gender quotas, predicting that quotas are more likely to be adopted in legislatures with shorter career tenures. We test this theory using Event History Analysis with an original dataset on sixteen Latin American lower chambers from 1988 onward, using reelection rates as a proxy for career patterns. Consistent with our predictions, our results show that gender quotas are adopted more quickly in legislatures with lower reelection rates. These findings underscore the strategic considerations behind gender quota adoption and the potential obstacles posed by male legislators' ambitions to women's political inclusion.