With reporting by Rikki Martinez
"He was very specific about the lyrics -- he wanted them to be like, 'bear, Paddington, station' and I wanted it to be a little more abstract," Stefani told MTV News.
The pair had been given a version of the song to work with and decided to go in and rewrite it to fit the film.
The duo -- who have a very "free-flowing" collaboration style, according to Stefani -- finally came to an agreement after viewing the flick with the No Doubt singer's children, who she says "have special ears that hear things that are good."
"At the end of the day we screened the movie at my house with the kids and watched the whole thing and the song came on and he was so right," Stefani said of Pharrell's take on the tune. "He had such a great instinct for these things. He has a way of really channeling feeling."
The video for "Shine" dropped earlier this week -- with "Paddington" hitting theaters Friday (January 16).