BERKELEY, Calif. (CBS Sacramento) – That’s going to leave a mark.

More than 17,500 people in less than a decade have had genital injuries caused by zippers, according to a recent study.

Researchers at the University of California, San Francisco discovered that about 900 men ages 18 and older each year in the U.S. go to emergency rooms due to their penis being caught in a zipper.

The study, which was published in BJU International, estimated that from 2002 to 2010, about 17,616 people went to the ER for zipper-induced genital injuries. The data is based off a sample size of 100 hospitals surveyed, which found that 523 of 2,695 cases of penile injury involved zippers, good for more than 21 percent of the cases.

Penile injuries relating to zippers paced ahead of penile injuries based on bicycle injuries among adult men, according to the study.