Attention all men: You might want to keep your laptops, smartphones and other Internet-browsing tools away from the family jewels.

A new study, albeit a small one,  suggests that using Wi-Fi may damage sperm and decrease a man’s fertility. The cause, according to Reuters Health, is electromagnetic radiation generated by wireless communication.

In the study, published in the journal Fertility and Sterility, researchers took semen samples from 29 healthy volunteers and placed them under a Wi-Fi-enabled laptop connected to the Internet. After four hours, the semen suffered – 25 percent of the sperm were no longer swimming and 9 percent of them showed DNA damage. Semen samples kept near a laptop that was turned on but not connected to the Internet showed minimal damage, as did samples that were stored separately.