The Biden administration is taking new measures that would limit the spread of 3D-printed guns. The Justice Department has issued a final rule with multiple measures restricting the sale and distribution of “ghost guns,” including a requirement for federally licensed dealers and gunsmiths to serialize any unmarked firearm (such as a 3D-printed gun) before selling it to a customer. You couldn’t print a gun at home and sell it to a store without some ability to trace its origins.

The rule also includes several other restrictions that aren’t aimed at 3D-printed weapons, including an effective ban on unserialized “buy build shoot” kits by treating them as firearms subject to strict licensing and background check requirements. The DOJ will also treat guns with split receivers as subject to regulations, and demands that licensed dealers keep “key records” until they shut down, not just for 20 years.

The move is the latest in a back-and-forth fight over attempts to regulate 3D-printed guns. After a case over Defense Distributed’s 3D-printed pistol bounced through courts (including the Supreme Court), the Trump administration’s State Department reached a settlement that legally allowed these homemade weapons. States sued the administration over alleged constitutional and procedural violations, earning a ban on the technology (albeit one with a claimed loophole). A judge determined that the Defense Distributed settlement violated procedural law, but the Trump administration tried to override that by transferring regulation to the Commerce Department and making it difficult to implement substantial limits. State attorneys general sued over the rule change.

A rule like this won’t stop individuals or black market operators from making and trading 3D-printed guns. It might, however, discourage licensed dealers from letting those guns enter their shops. If nothing else, it signals a reversal from the previous administration’s stance — the current White House sees untraceable 3D-printed firearms as significant threats.