Sam Smith attends the 60th Annual GRAMMY Awards at Madison Square Garden on Jan. 28, 2018 in New York City.

Add Sam Smith to the growing list of celebrities who’ve contracted COVID-19.

In a new interview with Apple Music’s Zane Lowe, Smith says they caught the bug while in the U.K., but like many others self-diagnosed, stayed in and let nature take its course.

“I didn’t get tested but I know I had it. 100 percent had it. Everything I’ve read completely pointed to that. So yeah, I think I definitely had it," Smith recounts.

Soon after falling ill, Smith’s sister started showing the same symptoms. So they locked it down for a three-week stint in self-isolation to protect those near and dear.

"As everyone was kind of really on lockdown, that’s when I got over it, luckily."

With the doors closed to the outside world, Smith needed a release. The Brit felt the urge to sing, and create. "The first two weeks, I just wanted to sing. I don’t want to sing my songs, I don’t want to sing and film it. I just want to walk around the house and sing.” In week three of self-quarantine, Smith lost the urge.

The pop hitmaker hit a groove and the writing juices started flowing. Smith is back on form, releasing a new collaboration with Demi Lovato, "I'm Ready," and performing a duet with John Legend for the historic Together At Home concert this past weekend.

Smith also spoke with Lowe about quarantine playlists, the recent decision to not only postpone, but rename their upcoming third studio album (originally titled To Die For), and more.

Watch below (from the 1.30 mark).