The "Complicated" singer split from the Nickelback frontman last September after two years of marriage, but the 31-year-old star said they will always be close, both personally and professionally, reported E! online.
"We started working together in the studio, and we do still work together, and we've maintained our friendship like we love each other deeply," Lavigne said.
"And that's something we want to keep, and that's important to us.