Netflix is reportedly trying out a new higher-priced subscription service, prompting fears that it could lead to higher monthly bills for subscribers.

“The streaming TV company, which has more than 125 million subscribers worldwide, is testing a higher-priced premium ‘Ultra’ subscription in Europe offering 4K Ultra HD video with High Dynamic Range (HDR) quality and the ability to watch on four screens at the same time for 17 Euros (€16.99, or about $20),” USA Today reports.

Netflix wasn’t offering details about the tests, but said in a statement: “We continuously test new things at Netflix and these tests typically vary in length of time. In this case, we are testing slightly different price points and features to better understand how consumers value Netflix. Not everyone will see this test and we may not ever offer the specific price points or features included in this test.”