There’s nothing quite like the frustration of waking up in the middle of the night to find a corner of your fitted sheet has popped off the mattress. You tug it back into place, only to have it slip again a few hours later. Over time, the elastic that hugs your mattress corners loses its grip, and what used to be a perfect fit becomes a nightly wrestling match. The good news is that you don’t have to toss those sheets in the trash or rush out to buy a new set. With a few basic tools and a little bit of know-how, you can give that sagging elastic a second life. This fix is simple enough for any homeowner to tackle, and it will save you money while keeping your bed looking crisp and neat.

Before you dive into the repair, take a look at the elastic casing along the edges of your fitted sheet. Most sheets have a hemmed channel that holds a continuous piece of elastic. Over time, that elastic can stretch out, break, or simply lose its snap. Sometimes the problem isn’t the elastic itself but the stitching that holds it in place. Loose threads or a torn seam can let the elastic slide around, making it useless. Start by inspecting the corners and the sides. If you see the elastic poking out of a hole, or if the hem is ripped, you’ll need to patch that first. A simple needle and thread, or a quick pass on a sewing machine, can close any gaps. If the elastic is still intact but just loose, you can tighten it without replacing the whole thing.

The most straightforward method is to shorten the existing elastic. Turn the sheet inside out so you can see the hem. Find the point where the elastic is sewn in place at the end of a corner. Usually, the elastic is anchored at the seam that joins the side and end panels. Using a seam ripper or small scissors, carefully open a few inches of the hem near one corner. Don’t cut the elastic itself—just the stitching that closes the casing. Once you have access, pull the elastic out a little so you can work with it. Now, decide how much shorter you want it. A good rule of thumb is to shorten it by about two to three inches per corner if the sheet is slipping off frequently. Cut the elastic, leaving a tail long enough to overlap and sew. Overlap the ends by about an inch and sew them together securely with a zigzag stitch or a few tight straight stitches. Then tuck the new connection back into the casing and sew the opening closed. Repeat this process on each corner. You’ll notice an immediate improvement in how snugly the sheet fits.

What if the elastic is completely shot—broken, dry-rotted, or so stretched that tightening won’t help? In that case, you can replace it entirely. This takes a bit more time but is still a weekend-friendly project. Remove all the old elastic by cutting open the hem along the entire perimeter of the sheet. Be careful not to cut the fabric. Pull out the old elastic and measure the length of the hem channel. You’ll need new elastic that matches this length, minus a bit for tension. Most mattress sizes have standard measurements: for a twin sheet, about 180 inches of elastic should work; for a queen, aim for 200 inches; for a king, 220 inches. Buy ¼-inch or ½-inch flat elastic from any fabric store or online retailer. Thread the new elastic through the casing using a safety pin attached to one end. Work it all the way around, making sure it doesn’t twist. Once it’s through, overlap the ends by an inch and sew them together. Then stitch the hem closed. This total replacement gives your sheet brand-new holding power, and it often costs only a few dollars.

If sewing isn’t your thing, or if you want a no-stitch solution, there are quick fixes you can try. Elastic sheet suspenders—those plastic clips with a strap that attach under the mattress—can work wonders. You clip them onto the corners of the sheet and then tighten the strap so the sheet stays put. They’re inexpensive and available at most home stores. Another option is to apply a thin strip of fabric glue or hem tape along the inside of the hem to create friction. This works best for sheets that are only slightly loose, not completely shot. Just be careful not to use too much glue, or it might become stiff and uncomfortable against your skin.

While you’re working on your sheets, take a moment to check the mattress itself. Sometimes the problem isn’t the elastic—it’s that the mattress is too thick or too thin for the sheet. Modern mattresses can be surprisingly tall, especially pillow-top models. If your sheet’s pocket depth is too shallow, even new elastic won’t hold. Measure your mattress height and compare it to the sheet’s specifications. Many sheet sets now come with deep pockets, but older ones might not. If that’s the case, consider adding a mattress topper or buying a set of sheet corner clips that adjust to different depths.

A final tip: washing and drying your sheets on high heat can accelerate elastic fatigue. To make your repairs last longer, wash sheets in cool or warm water and tumble dry on low or medium heat. Remove them while they’re still slightly damp to reduce stress on the elastic. With a little care and a small investment of time, you can keep your favorite sheets snug and secure for many more nights.