The 72-year-old, who has played Patrick Trueman on the soap for 11 years, said that there are still many moments of levity on the show, despite its somewhat miserable reputation.
Walker is quoted as telling Inside Soap that this is the reason he is still happy to work on the programme, despite his advancing years.
He said: "The camaraderie keeps me going. Being in EastEnders is challenging at this stage in my career, and the demands are far greater than they used to be.
"Turning up on set every day and keeping the character fresh is hard work, but I do it with a smile.
"As long as Patrick continues to run the gauntlet of emotions and there's humour in the show, I'll be happy."
Walker said last year that he would "never retire" from EastEnders, arguing that actors are supposed "to drop down on the job".
Patrick has recently been left distraught by Heather Trott's murder, but things start looking up for him when he embarks on a fling with Tanya Branning's mother Cora Cross.
Walker commented: "Patrick enjoys the thrill of the chase - and the conquest!
"He'll continue to investigate the prospect and see what happens between him and Cora."