BOISE, Idaho (AP) — Idaho's highest court says the state must enforce legislation banning lucrative instant horse racing terminals.

In a unanimous decision issued Thursday, the court ruled that Gov. C.L. "Butch" Otter's veto of the legislation was invalid because he didn't complete it within the required five-day time span.

The court said Secretary of State Lawerence Denney must certify the law, making the machines illegal. There are currently about 250 of the machines installed in three locations across Idaho. Known as instant horse racing, the machines allow bettors to place wages on prior horse races with no identifiable information.

Idaho lawmakers approved legalizing the machines in 2013, but passed the legislation banning them earlier this year after critics argued the machines were essentially illegal slot machines. Horse racing track owners have countered the terminals are needed to keep their industry afloat.