To become a truly savvy traveler, even the best deals on luggage can only get you so far. Sure, any rookie can effectively pack a suitcase. But some of us travelers are willing to go the extra mile. It takes dedication and craftiness to, say, transform your pillow into a secret carry-on bag.

This idea comes from the viral TikTok pillowcase hack to sneak more clothes on board via—you guessed it!—a pillowcase. Of course, you’re not actually “sneaking” any secrets past TSA. Still, this is the worthwhile hack for anyone looking to maximize their carry-on potential. Here’s how to turn your pillow into a carry-on, and why you might want to invest in the right pillowcase to get the job done.

The pillowcase hack is simple, yet effective. All you have to do is simply remove the original padding from inside a pillow and replace it with your clothing. This trick works best with plusher clothes like sweatpants and sweatshirts.

With this hack, you can now travel with a few extra outfits than you managed to squeeze into your suitcase. And here’s the best part: There’s no carry-on charge for a neck pillow.

You don’t have to use any old pillowcase, either. Consider investing in a proper neck pillow to get the job done, like Dot & Dot Twist Memory Foam Travel Pillow. This pillow is especially appealing because of its snap closure—perfect for removing the memory foam and replacing it with your cushiest clothing.

Other travelers attest to the pillow-turned-carry-on method: One Amazon reviewer said they’re a carry-on-only flier who removed the Dot & Dot’s memory foam and replaced it with clothes that they “would’ve packed anyway,” and that everything “worked like a charm.”

So the next time you have a flight, throw in an extra pillowcase. If you overpack for your return flight, you’ll be able to make some extra room in your suitcase and gain an extra pillow, all in one smooth move.