Blake Shelton and Michael Bublè have been friends for years, but that doesn’t mean the country singer wasn’t nervous about asking the Canadian crooner for a favor.

The two became close after The Voice judge had a hit with Bublè’s song “Home” in 2008. Shelton told CBS Local that Bublè was “excited he had a country hit as a songwriter” and even asked him out on the road for a few performances.

“We ended up singing it together a few times in his concerts and we filmed a David Foster special together where we sang the song together,” he said.

But even though the two had performed together, Shelton still felt worried about asking the singer’s permission to use his song once again. This time for his holiday album, Cheers, It’s Christmas.

“I had the idea of doing a Christmas version of ‘Home’ because the song would kind of lend itself to the holidays anyway,” he said. “That’s when you really miss home.”

He later sent Bublè an email asking if he would be interested in writing a Christmas version of the song. Shelton hoped the singer would not only lend his words, but his vocals to the song too.

“I felt really stupid asking that question because he is Michael Bublè,” Shelton admitted.

But it turns out his anxiety was unwarranted because Bublè was more than happy to help. The two worked together so well, Bublè even joined Team Blake as a mentor on the current season of The Voice.

Fans can see the two perform together on Buble’s upcoming special, Home For The Holidays, airing December 10 at 10pm EST on NBC.

Contest: Win a chance to spend Christmas in Hollywood with Blake Shelton at the finale of The Voice!

Check out the latest version of “Home” on Shelton’s holiday album Cheers, It’s Christmas, which is out now.

- Shannon Carlin, CBS Local