Former Second World War Sergeant Major Buster Martin maintains a fleet of 100 vans for a plumbing firm, reports the Sun.
He retired at 97 but he applied for his current job after three months because he found retirement 'boring'.
He said: 'There's nothing like a good day's hard grafting. I'm going to work until I die - which I reckon will be 125.
'There's nothing doddery about me. I love getting my hands dirty and bossing these youngsters about.'
Buster, who is 100 in September, puts his good health down to 'the odd daily pint, a walk to the library and press-ups'.