Avril Lavigne

So much for her happy ending.

Avril Lavigne has filed for divorce from husband Deryck Whibley, according to TMZ.

According to the documents obtained by TMZ, Lavigne, 25, cited irreconcilable differences for the end of their three-year marriage. The "Complicated" and "My Happy Ending" singer lists their official separation as Sept. 4. Lavigne did not ask for spousal support and indicated she does not want to have to pay Whibley any money.

Avril Lavigne and Deryck Whibley split

"I am grateful for our time together, and I am grateful and blessed for our remaining friendship ... Deryck and I are separating and moving forward on a positive note," Lavigne said in a message posted last month on her Web site.

Whibley, the 29-year-old lead singer of Sum 41, wrote a note on his band's MySpace page about the separation: "Our decision to part ways is amicable and she holds a special place in my heart and forever will be a great and amazing friend."

Lavigne's rep did not immediately return calls for comment.