The Apple Watch may have its first big scandal. According to numerous reports, one of the device’s sensors doesn’t work through darker tattoos, and a new report from iMore seems to back up those claims.

Specifically, the issue has to do with the watch’s heart rate sensor, which the device also uses to confirm it’s still pressed against your wrist. With that connection lost, the Apple Watch can’t read your pulse. It also requires you to enter the passcode every time you wake up the screen.

According to iMore, only darker tattoos are a real issue. Red or black ink throws the watch off completely, while purple, yellow, and orange aren’t quite as bad. Apparently “prominent scars” or any other skin abnormalities can trip up the heart rate sensor as well.

This shouldn’t be an issue if you have at least one wrist that isn’t inked, though for some people it could make the Apple Watch pretty useless. Hopefully the company can come up with a solution soon, though for now there haven’t been any official comments on “Tattoo-gate” out of Cupertino.