Attorneys general in Minnesota and New Jersey sued Glock on Thursday, accusing the company of making handguns that are easily modified to fire as illegal machine guns through a cheap add-on known as a “Glock switch.

New Jersey and Minnesota sued Glock on Thursday, calling on the gunmaker to stop selling firearms that can be adapted with dime-sized switches to fire up to 1,200 rounds a minute.

The two suits claim the company’s leaders have known for decades that significant design characteristics of the weapon make it susceptible to conversion to a machine gun.