Wedding details are still under wraps, but a source did say that Kroeger proposed with a 14-carat diamond ring.
Avril, 27, and Chad, 37, co-wrote a song together for Lavigne’s upcoming fifth album. On Aug. 19 she thanked Chad for his help via Twitter, "That's a wrap boyz
"A romantic relationship blossomed as they spent time writing together," a source told People.
This will be Chad’s first marriage and Avril’s second. She was married to SUM 41’s Deryck Whibley from 2006 to 2009.