The Anthropic Long-Term Benefit Trust (LTBT) is an independent body designed to align the corporate governance of Anthropic with its mission of developing and maintaining advanced AI for the long-term benefit of humanity. The Trust has five financially disinterested members who will select and remove a portion of the Board, growing over time until a majority is elected. This structure aims to fine-tune corporate governance to address the unique challenges and opportunities presented by transformative AI. The LTBT is paired with Anthropic's Public Benefit Corporation status, which already aligns its governance with its mission. However, the Trust provides additional accountability and incentives for directors to balance public interests with financial interests of stockholders, particularly in key decisions where consequences reach far beyond Anthropic. The Trust's design is an experiment, informed by corporate governance scholars and practitioners, and its gradual "phase-in" allows for course-correction as it becomes more mature and has profound effects on society.