'Good Omens' star Michael Sheen expecting child with girlfriend

July 18 (UPI) -- Good Omens star Michael Sheen is going to be a dad of two.

The 50-year-old actor announced in a tweet Wednesday he's expecting a baby with his girlfriend, aspiring actress Anna Lundberg.

Sheen is already parent to 20-year-old daughter Lily Mo with ex-partner Kate Beckinsale. He referenced Good Omens, an Amazon Prime series that follows the angel Aziraphale (Sheen) and the demon Crowley (David Tennant) as they work to prevent the coming of the Antichrist, in his post.

"Very happy to let everyone know that my partner Anna and I are expecting a little angel of our own. (Just to be clear - we're having a baby!) #nottheantichrist," Sheen wrote.

The Good Omens official Twitter account was among those to congratulate the couple online.

"Just don't let the @chattering_nuns deliver your little angel. Congratulations, @michaelsheen! #GoodOmens," the post reads.

Sheen thanked fans for their well-wishes in a tweet Wednesday afternoon.

"To my new Good Omens online family - THANK YOU! Yes we'll try not to get mine & David's mixed up. No we won't call the baby Adam. Yes hopefully healthy & hoofless!" he joked.

Sheen split from Beckinsale in 2003 after eight years of dating and has since dated Sarah Silverman and Aisling Bea.

Good Omens is based on the Neil Gaiman and Terry Pratchett novel of the same name and debuted on Amazon Prime in May. The show co-stars Sam Taylor Buck, Adria Arjona and Michael McKean.