• Mandy Moore and husband Taylor Goldsmith announced on Instagram that they are expecting their second baby
  • The couple, who shares 15-month-old son Gus, is set to welcome another baby boy this fall
  • Moore said that they are "deeply grateful and excited" and that Gus will be the "best big brother"

Mandy Moore is going to be a mom of two.

On Friday, the "This Is Us" star, 38, took to Instagram to announce that she and husband Taylor Goldsmith, 36, are expecting their second baby together, another son, this fall. The couple is already parents to 15-month-old son August "Gus" Harrison.

Moore shared a snap of Gus sporting a T-shirt with the words, "Big Brother," alongside a message in which she expresses her happiness and excitement about their upcoming bundle of joy.

"One incredibly seminal chapter of my life just ended, and the next one, as a mother of two, is about to start… and are we ever so deeply grateful and excited. Baby Boy Goldsmith #2 coming this fall!" she wrote.

"[The] tour is gonna be slightly different than I expected, but I can't wait, and Gus is gonna be the BEST big brother!!" added Moore, who recently released her new album, "In Real Life."

Moore's post was flooded with congratulatory messages from fans and followers.

"Congratulations!!! So happy for you!" Claire Holt commented, while Melissa Arnot Reid wrote, "I'm so excited for this and your whole family."

"The best news ever!!" Hillary Kerr wrote.

"Gus is gonna be the best big bro!!!! We're so excited for you guys!" another follower commented with a red heart emoji.

Moore's husband also announced the happy news via his own Instagram account, sharing the same photo of their son and saying that he is the "happiest, luckiest person."

"Gus is gonna be the best big brother. @mandymooremm is gonna be the best Mom of 2," Goldsmith wrote. "There's a good chance I'm the happiest, luckiest person you know (or just follow), and now we're gonna double it."

In an interview with Health magazine earlier this year, the "A Walk to Remember" actress said that her wellness routine drastically changed after she and Goldsmith welcomed their firstborn in February 2021.

"It was so much easier when I was pregnant, to find the time to take care of myself," she told the magazine. "I was at the chiropractor. I was at acupuncture weekly. I had prenatal massages. And then as soon as baby arrives, all of that pretty much goes out the window. And it's such a bummer because I feel like I wish I could find the time to sort of incorporate some of those practices again, because they felt so good. But it's not feasible and so, again, I try not to get down on myself about it."

But Moore said Gus has changed her life for the better. "Not to sound cheesy, but all the clichés are true. Life is Technicolor now. It just makes sense in a way that it didn't before," she told Parents for the magazine's December 2021 cover story. "I had no idea that this degree of love existed in the world."

Mandy Moore hair
Mandy Moore, pictured on Jan. 21, 2018 in Los Angeles, lightened her hair after finishing work on “This Is Us” Season 2. Kelly Nyland/AFP/Getty Images