The 'Take A Chance On Me' singers, who came second on the ITV contest's 2008 edition, said they disagreed with criticism of panellists Gary Barlow, Tulisa Contostavlos and Kelly Rowland.
"I thought personally the judging panel last year was fantastic," JLS member JB Gill told The Mirror. "I think you could see the chemistry the judging panel had on screen and the year was a success generally.
"They had a new judge in Tulisa go on and win the show with Little Mix. All the judges have proven their worth to the show."
However, Marvin Humes said that he would be happy to see X Factor boss Simon Cowell return.
"It'd be great to for Simon to come back," he said. "He came back this year on Britain's Got Talent so who knows - he might make an appearance again on X Factor this year.
"It's his show - Simon is The X Factor, so it'd be amazing for him to take up a chair."
> JLS star Oritsé Williams should be 'X Factor' judge, says JB Gill
> JLS interview: 'We'd like to work with Adele on new album'
JLS are set to release their Sport Relief charity single 'Proud' on March 19.
Watch JLS in the video for 'Proud' below: