The Democratic National Committee has selected bank board member and Clinton ally Barney Frank to co-chair the party’s rules committee, a move that could aggravate Bernie Sanders’ attempt to push his anti-big bank agenda at the Democratic Convention in July.

Frank, a former Massachusetts congressman who introduced the 2010 Dodd-Frank Wall Street Reform and Consumer Protection Act, is a vocal critic of Sanders’ plan to break up big banks. He is also on the board of directors of a bank worth $29 billion as of June 2015, and has said that he is “very supportive of banking.”