If you are visiting family in December and you’re flying on Spirit Airlines, be ready to fork over a couple more dollars to check a bag.

Airlines have long charged higher ticket prices during peak travel periods, but this is the first attempt by low-cost Spirit to use the same approach during the holidays, spokesman Paul Berry said Monday.

On the “options and extras” page of its website, Spirit is telling customers that “we’re encouraging customers to pack a bit lighter” to make room for everyone’s bags during the holidays. Spirit will add $2 to checked-bag fees between Dec. 18 and Jan. 5, similar to a surcharge this summer. Checking a first bag on Spirit normally costs $21 to $100, depending on whether you pay while booking your ticket or wait until you get to the airport gate.

Spirit often charges lower fares than competitors but makes up some of the difference in more and higher fees. In the second quarter, Spirit’s average fare was $84.75, about half that at Southwest Airlines, which bills itself as a low-fare carrier. But Spirit also took in $55.15 per passenger in fees.

With those fees, Spirit relies on ticket prices for just 61 percent of its revenue. The industry average is 75 percent, according to figures released Monday by the U.S. Department of Transportation.

Jay Sorensen, who tracks so-called ancillary revenue at airlines, says other carriers have charged higher prices for extras such as faster airport screening during peak demand, and that technology could help spread the practice.

“Philosophically, the airlines are on board with this if there is sufficient demand,” he said.

Airlines stocks fell along with the broader market on Monday. Shares of Spirit Airlines Inc., which is based in Miramar, Florida, dropped $3.15, or 4.4 percent, to $68.56, but remained ahead 51 percent for 2014.

(AP)