James Martin/CNET

Spotify wants you to stream music, but only if you pay for it with either your money or your time.

The service is updating its terms of service, effective March 1, to make it clear that the use of ad-blockers and similar services that prevent ads from playing is not allowed. And it can terminate your account without warning if you use them.

"We've updated our user guidelines, making it clear that all types of ad blockers, bots, and fraudulent streaming activities are not permitted," Spotify said in an email sent Thursday.

This shouldn't be confused with the "Active Listening" feature Spotify has been testing in some territories since last August, which lets listeners choose to skip some ads if they don't want to listen to them.

Spotify offers both its free, ad-supported tier and an ad-free subscription tier for $10, £10 and AU$12 per month. According to Digiday, Spotify already has detection measures in place in order to find users on the free service using an ad-blocker. The music service also reportedly estimated that 2 million users are using an ad-blocker or a modified app to avoid ads, which is about 2 percent of its ad-supported monthly users.

Spotify did not immediately return CNET's request for comment. Many ad-supported websites and streaming services already prevent users from viewing content if an ad-blocker is installed, typically by alerting a customer to this and requesting that they turn ad-blocking off in order to read the page or watch a video.