Google says that a small number of Pixel phones have broken microphones that need to be sent back for replacement.

The issue is seemingly not that widespread. Google claims the issue is present on less than 1 percent of devices — the company also announced that it would replace defective phones last month, and it went largely unnoticed until now.

Google says the primary cause for Pixels having microphone issues is a “hairline crack in the solder connection on the audio codec,” which causes all three of the device’s mics to go out at once.

The issue has apparently been known about for several months now. Google says it’s been “taking additional steps to reinforce the connection” since January and that phones built or refurbished since then should be fine.

In an email, a company representative told The Verge that it’s “actively investigating” the issue and pointed to support posts from product management VP Brian Rakowski that summarize what’s going on.

Rakowski posts say Google will replace any phone affected by the problem. If you bought it through a third party, this may mean going without a phone until you get the replacement in; but customers who bought directly from Google can get a new device shipped out to them before they return their existing one, so long as they’re fine with a hold on their credit card.

Despite the Pixel coming out in October, Google is still struggling to keep it in stock pretty much anywhere. This issue doesn’t seem to have had anything to do with the constant shortages we’ve seen; but, on the bright side, those shortages may have meant more people ending up with fixed Pixels, instead of the ones that can suffer from a broken mic.

Update March 9th, 1:40PM ET: This story has been updated with comment from Google.