Conservative media’s false claim that Bill Clinton banned guns on military bases is back in the news after being repeated by Republican presidential candidate Donald Trump.

Following the mass shooting at Washington, D.C.’s Navy Yard facility in 2013, conservative media sought to pin blame on President Clinton by seizing on a March 1993 Army regulation that they claimed banned the carrying of guns on military bases. In fact, the 1993 regulation came from a 1992 directive issued under George H.W. Bush that became “effective immediately” in February of that year. (The Bush directive actually allows guns to be carried on military bases under a substantial number of circumstances and military experts have said more permissive gun carrying rules are a bad idea.)

Although this falsehood led to the National Rifle Association’s news show issuing a rare correction, it’s been given new life after being repeated by Trump and subsequently trumpeted by the right-wing media echo chamber.

More: Donald Trump Revives Conservative Media’s False Claim Bill Clinton Banned Guns on Military Bases