Are you stressed about getting all of your gifts perfectly wrapped for the holidays? A new study says: don’t be.

Researchers at the University of Nevada found that poorly wrapped presents make people happier than perfectly wrapped ones. This is because, in part, perfect-looking presents look so great on the outside that whatever’s inside may not live up to expectations. If a gift looks sloppy, though, the recipient is likely to be pleasantly surprised by the actual gift. They also appreciate the effort that was made. The gratitude and surprise leaves them feeling happy and joyful.

One of the study’s co-authors, Jessica Rixom, Ph.D., got her idea for the study from her time working at a chocolate shop. She explained,

“They offered a wrapping service, so I learned how to wrap very neatly with crisp edges, just the right amount of paper, etc. I started wrapping my own gifts that way and many years later, when wrapping presents with a friend, I noticed that all of the gifts in my pile were neat while all of theirs were messy, even though they were trying. This made us wonder whether the way the gift was wrapped would have any influence on how the gifts themselves were perceived and that’s how it started.”

The study tested what Rixom and the other researchers call “expectation disconfirmation theory.”

“Based on participants’ answers to various questions, it suggested that the reason why this happens is because the neat wrapping sets higher expectations for the gift inside, which makes it harder for the gifts to live up to those expectations. When the gifts are unwrapped, the recipient is a bit disappointed whereas when it’s wrapped sloppily, expectations are lower so the gift is more of a pleasant surprise.”

So, don’t worry at all if your gifts look like they were wrapped by a five-year-old. It doesn’t take away from the power of the gift—it might even make it stronger.