Mandy Moore and husband Taylor Goldsmith are expecting their first child, a baby boy

Chrissy Metz is over the moon about pal Mandy Moore's pregnancy!

In a new PEOPLE interview, the actress says she was "so excited" when she first found out that Moore and husband Taylor Goldsmith are expecting their first child, a son.

"I know that she plays my mom on TV and that we're friends, but I don't know, it was just really special and it made me very emotional," Metz says of her This Is Us costar. "So I'm very, very happy and excited for them."

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Mandy Moore, Chrissy Metz
Mandy Moore and Chrissy Metz
| Credit: Matt Winkelmeyer/Getty
Mandy Moore pregnancy
Mandy Moore and Taylor Goldsmith
| Credit: Jenna Jones

Moore and her husband first announced their exciting baby news last month.

"Baby Boy Goldsmith coming early 2021 💙," the proud mom-to-be, 36, wrote alongside several black-and-white snaps that showed the couple beaming and showing off Moore's baby bump.

In a sweet nod to their time together onscreen, Metz congratulated Moore in the comments section by writing, "The Goldsmith Three! ❤️💓❤️."

Of course, Moore had another big occasion to celebrate last month: Metz's birthday.

Paying the love forward, the actress and singer shared a touching tribute to her real-life pal and TV daughter.

"Happy Birthday, @chrissymetz. To know you is to love you. You are an absolute beam of light in this world and I'm so grateful that the #thisisus journey brought us into one another's orbit," she wrote. "Watching the world collectively fall in love with all that you are (singer-songwriter, author, podcast host, etc...) over these last few years has been such an immense joy."

"I can't wait to see what you do with this next chapter in life. Love you, Mitzy!!" she added. "Can't wait to social-distance squeeze you soon!! Xoxoxo."

This Is Us' two-hour season 5 premiere airs Oct. 27 at 9 p.m. ET on NBC.