Simon Cowell's 'Mr Nasty' side returned at The X Factor bootcamp over the weekend.
The X Factor 2017's bootcamp auditions were held at Wembley Arena over the past three days.
For the first time in a good few years, there was an audience present to watch the performances alongside the judges.
And they saw Simon laying into some of the less than talented contestants, the Daily Mirror reports.
Harsh putdowns from the music mogul apparently included telling one act: "You’ve let yourself down. It looks like you don’t care and you didn’t come here to win."
A source told the tabloid: "He has never lost his focus but Simon has definitely been more relaxed in recent years. But when things went wrong this weekend the old acid-tongue and killer putdowns were back
“He is very excited about the talent on the show this year but he is a perfectionist at heart and wants to make sure the right people go through so he didn’t hold back.”
Adding a live audience to the bootcamp stages is the latest in a raft of changes set to be made to this year's series.
It's been reported that The X Factor 2017 will 'encourage' contestants to sing their own music as part of the major revamp.
Another big overhaul will be the live shows which will reportedly be cut to six weeks, but with acts performing and leaving on both the Saturday and Sunday night each weekend.
Both nights will also see guest artists perform in a bid to attract back viewers following one of the least watched series in 2016.
"Ratings plummeted and Simon knew a drastic revamp was needed," a source told The Sun. “The Saturday night show became so tedious as there was rarely any drama which an eviction would bring.
“ITV believes transforming it is the right decision. It means all singers will perform on both Saturday and Sunday evenings, with acts being eliminated both nights."
Following bootcamp, contestants will progress through to the dreaded six chair challenge.
The X Factor typically launches at the end of August on ITV.