The couple got engaged last fall.
On Wednesday, Shelton appeared on The Tonight Show Show Starring Jimmy Fallon, where he was asked about the first song he'll dance to with Stefani as husband and wife.
"I think it's called the wedding march," Shelton, 44, quipped before host Fallon clarified he meant his first dance song.
Shelton then pulled out his phone and said, "It's 'If You Leave' from the Pretty In Pink soundtrack. We talked about this. We both love the song. We're both fans of the '80s, why not? Don't you think that would be a great one, though? We've literally talked about that."
The 1981 classic from the Orchestral Manoeuvres In the Dark has some pretty great lyrics. "If you leave, don't leave now/Please don't take my heart away/Promise me just one more night/Then we'll go our separate ways," the group croons.
The couple is very excited for their big day, but 51-year-old Stefani plans to keep their wedding minimal.
"We're keeping it very simple. Really simple," the "Let Me Reintroduce Myself" singer said last month on Late Night With Seth Meyers. "I think the guest list will not have a lot of musicians. It'll be like my mom and my dad. It's literally going to be just family. We are looking forward to that, though."