Facebook is shedding young users fast, according to a recent forecast by digital market research company eMarketer.

The social network giant will lose about two million users under the age of 24 in 2018, eMarketer estimates. According to the report, the platform will end the year with around 5.8 percent fewer users ages 18 to 24 than it had at the end of 2017 and 5.6 percent fewer users aged 12 to 17 during the same period. Additionally, the number of U.S. Facebook users ages 11 and younger will decline by 9.3 percent.

It’s the first time eMarketer has predicted a decline in the number of U.S. Facebook users belonging to those age groups. Also for the first time, fewer than half of U.S. Internet users between the ages of 12 and 17 will access Facebook this year from any device at least once per month, according to eMarketer’s report.

US Social Network Users, by Platform, 2018

Facebook’s popularity among younger users has been  waning for some time, and while Facebook-owned photo sharing site Instagram has been stealing much of that audience, the worst omen for Facebook to come out of eMarketer’s report is the revelation that messaging app Snapchat now seems to be accounting for an increasing amount of Facebook’s user diaspora.

While Instagram will add 1.6 million users ages 24 and younger by the end of the year (totaling nearly 105 million, up 13 percent from the beginning of 2017), eMarketer predicts that Snapchat will see nearly two million new users in that demographic during the same period, up to an estimated 86.5 million users.

Facebook remains the largest social media site, and is still adding users overall every month — the site claims 2.2 billion monthly active users as of 2017’s fourth quarter, according to a recent forecast by Internet statistics company Statista — but its gains now come largely from members belonging to older age groups. eMarketer predicts the number of total Facebook users in the U.S. will hit nearly 170 million this year, revealing gains of only one percent from 2017, and the pool of total social network users accessing Facebook will also continue to dip by the end of the year.