This year, the world’s largest social network will see a decline among teen users in the U.S., according to a forecast by EMarketer. It’s the first time the research company has predicted a fall in Facebook usage for any age group.

EMarketer predicts 14.5 million people from the ages of 12 to 17 will use Facebook in 2017, a drop of 3.4 percent from the prior year. Teens are migrating instead to Snap Inc.’s Snapchat and Instagram, the photo-sharing app that Facebook owns, the research company said Monday in a statement.

Facebook has continued to grow around the world, with more than 2 billion users this year, but younger people are finding it less compelling, said Oscar Orozco, a forecasting analyst at EMarketer. The company needs to attract younger users so they build a Facebook habit that will carry into their adult years, when they become prime customers for Facebook advertising.

“Teens and tweens remaining on Facebook seem to be less engaged –- logging in less frequently and spending less time on the platform,” Orozco said. “At the same time, we now have Facebook-nevers, many children aging into the tween demographic that appear to be overlooking Facebook altogether, yet still engaging with Facebook-owned Instagram.”