A federal appeals court declined to strike down Massachusetts’s “assault weapons” ban, months before the Supreme Court is set to weigh in on the hotly contested Second Amendment issue.

A three-judge panel on the U.S. Court of Appeals for the 1st Circuit denied an effort by a trio of gun stores to revive a lawsuit that claims the Massachusetts law, which bars the sale, transfer, or possession of “assault-style” semiautomatic weapons, is unconstitutional under the Second Amendment. The law bans several of the most popular firearms in the country, including the AR-15.