James Van Der Beek to Be a Dad!

Credit: Charley Gallay/Getty Images for Vanity Fair

Dawson, get ready for daddy duty.

James Van Der Beek and his girlfriend, business consultant Kimberly Brook, are expecting their first child, the actor, 33, announced on Twitter Friday.

"Yes, it's true – the woman I love and I are expecting our first child," he wrote. "Currently experiencing joy on levels I never knew existed."

Van Der Beek — star of the NBC drama Mercy — began dating Brook last July.

Last June, UsMagazine.com was first to announce that the actor and his wife, actress Heather McComb, separated after nearly six years of marriage.