Gwen Stefani says Charli XCX and Sia gave her a ''gift''.

The 45-year-old singer - who is expected to release her third solo LP later this year - said enlisting the help of the solo stars has reignited her passion for music.

She told British Cosmopolitan magazine: ''Charli XCX, Calvin Harris, Miguel - they gave me a gift. And Sia she's a f***ing genius.''

Despite not meeting the 22-year-old 'Break The Rules' hitmaker, Charli, the 'Voice US' coach has nothing but praise for her.

In a previous interview with, she gushed: ''Yeah, the way that Charli and I worked together was that we really didn't work together. She wrote with Benny [Blanco] and then I wrote with Benny separately. I wrote her an email and was like, 'This is so weird that I haven't ever met you and now we have this song.'

''I think out of all the writers out there, male and female, I really like her style the most. I think that she comes up with really good melodies.

''I feel really lucky to work with her in the weird way that we did. It'd be interesting to actually be in the studio with her. I'd be intimidated. It's always awkward for me to be vulnerable when I'm in the studio with people, but sometimes really great stuff comes out of that. You just have to be brave enough to do it.''