Oklahoma Attorney General Gentner Drummond is taking action against a new pig welfare law in Massachusetts.

In a court filing, he says it would have negative impacts on the state’s pork producers. The law bans other states from selling or shipping pork to the state if they do not meet Massachusetts hog-housing requirements.

The Massachusetts law requires most uncooked pork sold in the state to come from pigs raised in enough space to lay down, stand up, fully extend their limbs and turn around freely.

Oklahoma is part of a 13-state coalition arguing the new law is unconstitutional. In the court filing, Drummond says it would have negative impacts on the pork industry and raise pork prices.

“This ban will significantly hurt pork producers in Oklahoma and across the nation,” Drummond said in a statement. “Oklahoma’s robust and responsible pork producers deserve a level playing field. It is imperative that Massachusetts consider the long-term, negative effects this unconstitutional measure will cause producers and consumers.”

According to the Oklahoma Department of Agriculture, the state is ranked ninth in the nation for hog production, with more than 2 million pigs.

The move comes after the U.S. Supreme Court upheld Proposition 12, a similar pig welfare law in California, earlier this year.