Not all reviewers were fans of Apple’s HomePod smart speaker when it launched last week, mainly due to its high price and the way it locks users into the Cupertino company’s ecosystem. But it seems there’s another issue with the $349 device: it can leave white rings on wood surfaces.

Both the Wirecutter and Pocket-lint noticed the problem, which has since been confirmed (and downplayed) by Apple. It seems the circular marks are a result of the HomePod’s silicon base interacting with certain oils used as a finish on wood furniture.

“An unhappy discovery after we placed a HomePod on an oiled butcher-block countertop and later on a wooden side table was that it left a defined white ring in the surface,” noted Wirecutter.

Apple told Wirecutter that “the marks can improve over several days after the speaker is removed from the wood surface.” If they don’t, it suggests refinishing the furniture or “try cleaning the surface with the manufacturer’s suggested oiling method.”

If you do own a HomePod, the best advice would be to avoid placing it on wooden surfaces with an oil or wax finish, as these are the only ones where the marks have appeared.

In a new support document, Apple claims it’s not unusual for speakers with silicon bases to leave marks on wooden surfaces, though it's hard to think of other devices with silicon feet that have the same problem. The company hasn’t said if it plans to reimburse customers whose furniture has been ruined by the HomePod, but they probably shouldn’t hold their breath.

In addition to requiring an iOS 11 device to set up the HomePod, the lack of Bluetooth compatibility, high repair costs, and inability to stream from non-Apple platforms like Spotify have made it a hard sell for all but the most hardcore Apple fans. It seems “Ring Gate” could give people another reason not to buy one.

Here is Apple’s "Cleaning and taking care of HomePod" support document.

HomePod is designed for indoor use only. When using HomePod, make sure to place it on a solid surface. Place the power cord so that it won't be walked on or pinched.

It is not unusual for any speaker with a vibration-dampening silicone base to leave mild marks when placed on some wooden surfaces. The marks can be caused by oils diffusing between the silicone base and the table surface, and will often go away after several days when the speaker is removed from the wooden surface. If not, wiping the surface gently with a soft damp or dry cloth may remove the marks. If marks persist, clean the surface with the furniture manufacturer's recommended cleaning process. If you're concerned about this, we recommend placing your HomePod on a different surface.