Illinois Democrats approved a new per-wager tax on online sports bets, adding another financial burden to consumers and threatening the state’s legal sports betting industry.

Beginning July 1, Illinois sportsbooks must pay $0.25 on each of the first 20 million bets placed statewide annually and $0.50 on every bet after that. FanDuel has announced it will begin charging a $0.50 fee on every wager starting September 1.

This follows a steep tax increase passed last year that already raised rates to as high as 40% for top operators.