We examine the wealth effects of three regulatory changes designed to improve minority-shareholder protection in the Chinese stock markets. Using the value of a firm's related-party transactions as an inverse proxy for the quality of corporate governance, we find that firms with weaker governance experienced significantly larger abnormal returns around announcements of the new regulations than did firms with stronger governance. This evidence indicates that securities-market regulation can be effective in protecting minority shareholders from expropriation in a country with weak judicial enforcement. We also find that firms with strong ties to the government did not benefit from the new regulations, suggesting that minority shareholders did not expect regulators to enforce the new rules on firms where block holders have strong political connections.