For its next act, Instagram could take on another major rival: YouTube.

The photo-sharing app is readying a feature that would let users post videos that last up to an hour long, according to a new report in The Wall Street Journal. Currently the time limit is 60 seconds in Instagram feeds and 15 seconds in Stories.

The report doesn't say exactly how such a feature would work, but it sounds like it could be an extension of Instagram Stories. The longer form video would be vertical, according to the Journal, and the company has reportedly had discussions with publishers and other "content creators."

It's not clear when the feature might launch, but it would be a major expansion for Instagram, which until now has focused on shorter videos.

But the move would open up new opportunities for the app to rake in ad dollars as longer videos could accommodate more ads. It would also help Facebook chip away at YouTube's dominance in video.

Like YouTube, Instagram also has a large community of influential users with large followings. Right now, the only way for those users to post extended videos is via a livestream, which doesn't contain ads.

Facebook likely wants to compete with YouTube for more than just ad dollars, too. YouTube's unseated Facebook as the most popular social network among U.S. teens, according to a study released by Pew research last week.

Though Instagram remains popular with younger users, it's a worrying trend for Facebook, which held the top spot in 2015, according to Pew.

Interestingly, a potential move into longer form video would also come at a time when Instagram is supposedly working on feature to get people to spend less time in its app -- not more. The company's planning a feature that will show users how much time they're spending in the app in order to ensure time spent is "positive and intentional."

An Instagram spokesperson declined to comment.