Little Oliver Hudd dreamed of finding buried treasure in his granddad's back garden.
But using his new metal detector for the first time he discovered something far more significant: a bomb!
The six-year-old's family alerted police and the area evacuated while the bomb squad dealt with the treasure hunter's dangerous discovery.
The bomb – weighing 8lb – was from the First World War.
Fortunately, it was found not to contain any explosives, but the family have been told not to dig in their garden in Dartford, Kent, any more in case they find a live one.
Oliver's mum Jenny Smith, 36, said: "We couldn't believe it. The first time he goes out with his metal detector and finds that."
His dad Jason tried the metal detector but without any luck. But as soon as Oliver touched it, it started beeping.
"He dug down and felt the spade hit metal. He kept digging and hit it a good few times with the spade before seeing the pointed end and realising it looked like a bomb.
"I think Oliver reckons he's always going to be finding exciting things now - a bomb in every field."
Oliver has been showing off pictures of his amazing discovery to his friends at school during show and tell.
His mother added: "The bomb disposal experts confirmed that it was a First World War bomb.
"They weren't sure why it was there - if it was a dud-bomb or a training tool - but they've told us not to dig up the area anymore in case there are more bombs, and with explosives in this time."