If you’re having trouble squeezing a new (or old) pair of shoes on, don’t fret. You can easily stretch the shoe with this simple trick we found over at Lifehacker.

As we all (hopefully) learned in school, water expands when it freezes. That means a small bag filled with water will stretch your shoe a bit as the ice forms. While you should be careful not to over stuff your shoe—lest you risk tearing it—a little extra give can mean the difference between comfort and searing pain all night long. When you’re done, break the ice out of the shoe.

To make this work effectively, try freezing the shoes (with the bags) overnight. Then, if you need more give, repeat the process again. Just make sure you don’t let the water leak into the shoes!