Avril Lavigne has come to the defence of estranged husband Chad Kroeger after the Nickelback frontman was targeted in a joke by Facebook co-founder Mark Zuckerberg.

The Skater Boi singer may have split from her rocker beau in 2015, but Avril was quick to jump in when Chad’s band became the butt of a joke by Mark.

It all began when Mark shared a YouTube video on Tuesday (20Dec16) in which he promotes the home artificial intelligence assistant Jarvis.

In the footage, Mark is seen asking Jarvis, voiced by Morgan Freeman, to play "some good Nickelback songs."

"I'm sorry, Mark. I'm afraid I can't do that," Jarvis replies. "There are no good Nickelback songs."

Mark then responds: "Good. That was actually a test. How about just play some songs that our whole family likes."

While the joke was taken as a tongue-in-cheek one by many, Avril appeared to take offence, taking to her Twitter account to pen a response to Mark, addressed to "Mark".

"Many people use your products -- some people love them and some people don't. Either way, you're allowed your musical opinion however, your jab at Nickelback is in poor taste," she wrote. "When you have a voice like yours, you may want to consider being more responsible with promoting bullying, especially given what's going on in the world today. #SayNoToBullying #TheJokeIsOld #NickelbackHasSoldOver50MillionAlbums."

Avril and Chad split in September 2015 after two years of marriage, with the Canadian pop star announcing the sad news on social media alongside a photograph from their wedding day.

She told fans, "It is with a heavy heart that Chad and I announce our separation today... Through not only the marriage, but the music as well, we've created many unforgettable moments. We are still and forever will be, the best of friends, and will always care deeply for each other. To all our family, friends and fans, thank you sincerely for the support."