With an internationally lauded approach to conserving Southern Ocean ecosystems (1), the healthiest marine ecosystems on Earth, the Commission on the Conservation of Antarctic Marine Living Resources (CCAMLR), has committed to adopting marine protected areas (MPAs) in the waters around Antarctica (2). But conflict over MPAs has led CCAMLR member states to disregard the best available science, distort the foundational rules of their convention, break trust, and threaten the integrity of one of the world's most well-regarded science-based multinational governance efforts. With negotiations resuming at the CCAMLR meeting beginning 17 October, we offer recommendations aimed at implementing effective Southern Ocean MPAs, upholding CCAMLR's mandate, and maintaining its global leadership in ecosystem-based management. Given the historic conservation and diplomatic success of CCAMLR and Antarctic governance writ large, if we cannot adopt meaningful MPAs in the Southern Ocean, it does not bode well for doing so in the rest of the high seas.