Dolly Parton‘s A Holly Dolly Christmas album includes collaborations with several artists, including Willie Nelson, Billy Ray Cyrus, and Jimmy Fallon. The late night TV star was invited by the country music icon to sing with her on “All I Want for Christmas Is You,” although she admits he was initially reluctant to join her on the project.

“A few years back I was on Jimmy Fallon’s show, which I love him. We just have this sweet connection,” Dolly shared on Apple Music Country’s Proud Radio with Hunter Kelly. “He had asked me if I would sing ‘All I want for Christmas Is You’ and I said, ‘Jimmy, I am so sorry. I don’t know that song well enough because I never learned it, because I knew I couldn’t ever sing it like Mariah so I just sing along on the radio.’ But anyway, I went home and learned it. I thought, ‘Well, I need to learn it at least, if somebody else asked me to sing it.’ So I did and when I got ready to put this together, I called Jimmy up. I said, ‘Hey, I learned that song, ‘All I Want for Christmas.’ Will you sing it with me on my record?’

“And he said, ‘Oh Dolly, I’m not a real singer. I just flew around,'” she recalls. “I said, ‘You are a real singer. I love your voice. Will you sing it with me?’ He said, ‘Only if you promise if I do it and it doesn’t sound good, you’ll take my voice off.’ I said, ‘I promise you that.’:

Fortunately, their duet turned out great, and found its place on A Holly Dolly Christmas.

“We recorded it and we love it,” Dolly boasted. “He loved it. He’s proud of it; I’m proud of it, and it’s one of my favorite songs on the album. I was hoping someday when I’m on Jimmy’s show that maybe Mariah might come and sing it with us. Wouldn’t that be cool?”

The 74-year-old previously revealed that A Holly Dolly Christmas was recorded over the summer, but she still worked hard to bring in the holiday spirit, even during the warm weather.

“When we were recording, we had the air conditioner down on real cool and we had Christmas trees and all that,” Dolly told  Sounds Like Nashville.  “So, I’ve put up Christmas decorations when I’m writing, and when we’re in the studio, we bring each other presents just for fun, keeping the spirit alive. At the end of the day we’d say, ‘Merry Christmas, see ya later.’”

Purchase A Holly Dolly Christmas at DollyParton.com.