The judges had reportedly not been speaking to each other this week following last Sunday's programme, where Walsh deliberated over voting to save Barlow's act Carolynne Poole or Rylan Clark.
The decision went to Deadlock, and it was revealed that Clark, mentored by Nicole Scherzinger, had been saved by the public vote. Barlow then left the arena.
At the beginning of tonight's show (October 13), Barlow said: "I thought last week was a disaster. I'm having trouble looking at Louis at the moment, let alone talking to him."
However when presenter Dermot O'Leary asked Barlow if he had forgiven Walsh, he replied: "Absolutely. It's a new day, Louis, shake hands."
The two judges then exchanged handshakes.
On his controversial decision, Walsh commented: "I just couldn't make up my mind, Dermot… I was scared!"
The X Factor continues on ITV1.