Apple just reintroduced a blood-oxygen reading feature to some Apple Watches last week, but a new lawsuit could force the company to turn it off again.

Following a decision that offered Apple a way to bring its Apple Watch blood oxygen tool back in the U.S., Bloomberg reports that Masimo alleges U.S. Customs and Border Protection "unlawfully let Apple Inc.

The feature was removed for US fans after health technology company Masimo sued Apple, claiming it willfully violated Masimo's intellectual property by way of its patented blood oxygen feature. As a result, the feature was temporarily disabled on the Apple Watch Series 9, Apple Watch Series 10, and Apple Watch Ultra 2.