Proxy firms that recommend to investors how to vote in company elections must disclose conflicts of interest that could be seen as influencing their advice, according to the Securities and Exchange Commission.

The SEC’s guidance, released on Monday, comes in response to critics such as the U.S. Chamber of Commerce who note that some proxy firms that counsel investors on voting matters including executive pay and the makeup of corporate boards also consult for those same companies. Institutional Shareholder Services Inc. is one such proxy adviser, Bloomberg says.

According to The Wall Street Journal, the SEC’s guidance may cause mutual-fund managers and other investment advisers to curb their reliance on proxy-firm recommendations in corporate elections by discouraging funds from offloading voting decisions to such firms. That’s because the guidance says that fund managers should review their proxy policies “no less frequently than annually” so proxies are voted in the best interests of their clients. They also would have to determine that the proxy firms they use have “the capacity and competency to adequately analyze proxy issues.”

Tom Quaadman, vice president of the Chamber’s Center for Capital Markets Competitiveness, called SEC’s action an “important first step.”