Canadian star Ryan Reynolds' superhero alter-ego has outed himself as a Nickelback defender in a new trailer for "Once Upon A Deadpool."

The trailer, titled "Respect the Back," parodies "The Princess Bride" with 42-year-old actor Fred Savage reprising his role as a child listening to a bedtime fairy tale.

When Savage takes a swipe at Nickelback, Reynolds' Deadpool character rises to the defence of the Alberta rock group that's often the punchline of jokes.

"I've had it with all this Nickelback hating, all right? You think that makes you cool with the cool kids in school, Fred?" Deadpool taunts.

Savage sticks to his guns, bashing Nickelback's music as "overproduced, formulaic, ear-garbage."

"Oh really? You know who might disagree with that? Facts," Deadpool retorts, before prattling off a list of Nickelback's musical plaudits.

"Fifty million album sales world-wide, 11th best-selling musical act of all time, Billboard's most successful rock group over the last decade, six Grammy nominations, and 12 Juno Awards -- those count -- six Billboard Music Awards, two American Music Awards, one People's Choice Award, Canadian and a partridge in a ... pear tree," he rants, throwing in an expletive for good measure.

Savage sheepishly tries to apologize, but Deadpool cuts him off. "I got to say, you were nicer as a kid."

The two make amends by launching into a duet of Nickelback's "How You Remind Me," holding hands as they rock out to the 2001 anthem.

Nickelback responded to the trailer with a riff on the song's lyrics, tweeting that it's "not like (Reynolds) to say sorry, we've been waiting on a different (Deadpool) story."

"Once Upon A Deadpool" is a PG-13-rated version of 2018's R-rated box office hit, "Deadpool 2."