The Miami Dolphins are encouraging fans to protect their right to legally bet on sports by voting no on an amendment to the Florida constitution that aims to increase the threshold required to expand gambling, including sports betting, in the Sunshine State.

Amendment 3 would strip the legislature of the power to expand gambling, including sports betting, and instead would require a voter referendum. Opponents of the amendment say it would “potentially close the door” on sports betting legalization in the state.

The Dolphins sent out a tweet Monday highlighting their concerns over Amendment 3, claiming that if the legislation passes, it “would effectively block any chance for sports betting in Florida.” The Tampa Bay Buccaneers also lobbied against the amendment, according to Floridapolitics.com.

Sportsbook operators DraftKings and FanDuel are opposing the amendment. Supporters of the amendment, which include Hard Rock International, which purchased the naming rights to the Dolphins stadium in 2016.