Star Trek: Discovery actor Anthony Rapp is engaged to his longtime boyfriend.

The 48-year-old Rapp announced on Saturday that he had asked Ken Ithiphol to marry him.

“So something happened tonight,” Rapp said in an Instagram post. “I asked @teerakeni if he would marry me and he said yes. I am so very happy and I'm so very thrilled to share this news.”

Rapp included a photo of the pair with Ithiphol, a leadership coach, proudly displaying his engagement ring.

The couple has been dating for four years, Entertainment Tonight reported.

In a 2017 interview with the outlet, Rapp talked about going on a safari in Tanzania with Ithiphol.

Rapp is known for originating the role of Mark Cohen in the Broadway production of Rent. He also reprised his role for the film adaptation of the musical. He plays Lieutenant Commander Paul Stamets on CBS All Access' Star Trek: Discovery.

(Related: Anthony Rapp says Lupita Nyong'o's story inspired him to talk about Kevin Spacey.)