Katy Perry has reportedly given John Mayer an "anti-Russell makeover".

The American singer is currently dating the singer/songwriter, following her divorce from Russell Brand.

John has been sporting a new look of late, cutting his long brown locks and ditching casual clothes in favour of a more polished look. It's been claimed Katy is behind his transformation.

"Katy's had it with the grungy bohemian rock star look. She's over it. She's basically given John an anti-Russell makeover," an insider told Heat magazine. "She likes him to wear smarter clothes - ones that don't smell - and to cut his hair. She's looking for a cleaned-up version of her ex."

The couple's relationship has been on and off, with Katy's pals initially said to be concerned about his reputation. John has dated stars such as Taylor Swift, Jessica Simpson and Jennifer Aniston and often discusses his romances - even likening Jessica to "sexual napalm".

Katy's loved ones have now been won over by the 35-year-old hunk, who celebrated his birthday with Katy last week.

"Her friends and family are starting to realise that John is more like Katy than Russell ever was. They have a great connection and are always laughing. Plus, John's schedule isn't as busy as Russell's was, so he can be with Katy whenever she has a break from work," the source added.

Katy is said to be considering taking the relationship to the next level and is thinking of relocating to be with her boyfriend.

"Things are getting more serious. Katy is even dreaming of them living together in New York - John already has a place there," the source explained. "She has sold the place she owned with Russell and started looking to buy somewhere else."