Apple Music is quietly undercutting Spotify.

The streaming service now offers subscribers the option to pay an annual fee of $99 rather than the $9.99 per month they'd otherwise owe, TechCrunchfirst reported. That's the equivalent of an $8.25 monthly fee, or $21 in yearly savings.

The move could help Apple lock in a more loyal set of subscribers as it battles Spotify for dominance over the space. Spotify, which boasts around twice as many paying users as Apple Music, is the only major streaming service to offer a free ad-supported tier, but its prices matched Apple's until now.

Still, Apple is hardly trumpeting the news of the price option. The plan isn't listed among the various tiers on Apple's main sign-up page; to find it, you have to open your account overview within the Apple Music app, and then head to the subscriptions tab under your account ID. That means it's only available to existing subscribers, though it'd be pretty simple to open an account and then switch over.

Before now, the same offer already existed in gift card form, but the new listing makes it official.

Spotify reminded everyone of its wide lead over the Cupertino company last week when it announced a new milestone of 140 million users, around 50 million of whom are paying subscribers. Apple currently has around 27 million.

With the backing of the richest company in the world, however, Apple Music can chip away at that advantage for as long as necessary.