Facebook’s Instagram said on Thursday it has fixed a bug that led to a temporary change in the appearance of its feed for a large number of users.

The bug led to a small test being distributed widely, the company said. As part of the test, some users had to tap and swipe their feed horizontally to view new posts, similar to its Stories feature.

The momentary change sparked a widespread outrage among users on Twitter, with several comparing it to Snapchat’s unpopular redesign.

Responding to a tweet and video of the horizontal scrolling, Instagram head Adam Mosseri tweeted, "Sorry about that, this was supposed to be a very small test but we went broader than we anticipated."

He later added that the update "should already be rolled back. If you're still seeing it you can simply restart your app and you should be good to go."

Some Twitter users were complaining about the new Stories-like approach in which users were reportedly told to tap side-to-side to look through posts, instead of scrolling vertically as they had in the past.

The company is still testing the side-to-side approach in "Explore," according to TechCrunch.