Want to leave your shoes on in the TSA screening line over the July 4 holiday weekend? Well, if you’re not younger than 12 or older than 65 (or a lucky member of the Pre-Check program), you could be in luck – The Transportation Security Administration is now using dogs to pre-screen passengers, sniffing for explosives before travelers get to the metal detectors and X-ray machines, MSN News reports.

This kind of passive screening can alleviate the need for more cumbersome procedures at the TSA checkpoint like removing shoes and taking laptops and bagged liquids out of luggage.

Airport security officials – along with Customs agents and local law enforcement – have used dogs for decades to detect contraband and gauge suspicious behavior.

The program likely works, says Jeff Prince, a professor at Metropolitan State University of Denver, by shifting passengers selected by TSA agents and screened by dogs into the fast Pre-Check line, which speeds up security for both the passengers selected for the special line and those in the now-shorter main security line. It also would relieve pressure on backed-up TSA agents.