The Transportation Security Administration, which manages security for all modes of transport in the U.S., currently uses Advanced Imaging Technologies to discover potentially dangerous items on a traveler’s person. Operating protocol generally allows people to opt out of the scan and have a physical screening instead, but TSA just updated its rules.

Agents can now deny a request to opt out of the scan, “as warranted by security considerations in order to safeguard transportation security.” The technology makes it easier to detect “both metallic and non-metallic threat objects.”

The Department of Homeland Security published the updated Privacy Impact Assessment on its website, and echoed the news on Twitter:

Generally, passengers undergoing screening will have the option to decline AIT screening in favor of a pat-down. Some passengers… 1/2

— TSA (@TSA) December 22, 2015

…will still be required to undergo AIT screening as warranted by security considerations in order to safeguard transportation security. 2/2

— TSA (@TSA) December 22, 2015

The updated policy comes as both airlines and passengers have grown increasingly concerned about travel security following the November Paris attacks and a plane crash of a Metrojet airliner over Egypt, which Russia has attributed to terror activity.