By Jordan Valinsky, CNN Business

(CNN) -- To fight spam, Twitter is dramatically reducing the number of accounts users can follow each day.

The social network announced Monday that people can now only follow 400 accounts per day, down from the previous limit of 1,000. Twitter said that the change was made to cut down on spammers.

"Don't worry, you'll be just fine," Twitter told users in a tweet.

Yoel Roth, Twitter's head of site integrity, explained in several tweets that the number 400 was picked because it's a "reasonable limit that allows people to follow the accounts they're interested in each day while stopping the most spam."

Twitter prohibits churning, the act of following and unfollowing the same account so a user can grow the number of his or her followers.

"We found that nearly half of all accounts who made more than 400 follows per day were churning," Roth tweeted. "That amounted to more than 20 million follows each day, and a high rate of blocks and spam reports — a clear signal that inorganic follows are super annoying."

"Every choice we make about our rules, limits, and spam-fighting systems has to work for hundreds of millions of people around the world, many of whom use Twitter in very different ways," Roth wrote.

It's the latest step Twitter has taken to stamp out spam.

Last year, Twitter limited the amount of coordinated posts users could make across multiple accounts. It stopped people from posting identical or substantially similar content across multiple accounts at once and stopped accounts from being allowed to "like" or "retweet" or follow other users from multiple accounts at once.

Twitter also tweaked its search using "behavioral signals" to push down more tweets that "distort and detract" from conversations and searches.

The company also has deleted automated accounts that violate its rules, by spreading false information and engaging in other suspicious activity.