Carly Rae Jepsen has revealed she has been "sworn to secrecy" about her collaboration with Justin Bieber.
The Call Me Maybe singer has worked with the teen heartthrob for her next album, but told MTV News that details are under wraps.
She said: "The Justin song, I'm kind of sworn to secrecy on because I think we want to release it together at one moment.
"But the rest of the album, I'm really excited for!"
Carly is also set to support the Baby singer on his upcoming Believe tour and confessed she is battling the nerves.
The 26-year-old said she doesn't know "what to expect" once she hits the road with Justin, whose presence usually causes scenes of chaos among excited young fans.
She said: "I did one or two shows with Justin. One in London and one in Mexico City, and all I can say is, like, 'Wow'. They were huge - 300,000 people in Mexico City. I was speechless."
Carly added: "I think that like in 10 years time I'm gonna sit back and look at everything that's happening to me this year and actually have a 'whoa' kind of a moment."