Do you own a valuable Harry Potter book with a tiny error in it?

A first edition of JK Rowling's debut novel, which features a rare mistake, is going up for sale at Bonhams Fine Books and Manuscripts Sale on 9th November in London - and it's expected to be auctioned for around £20,000.

The edition, first published in 1997, is one of only 500 hardback copies which contain the mistake.

To find out if your copy is one of those coveted few, turn to page 53 and keep an eye out for the repetition of "1 wand" in Harry’s list of Hogwarts school supplies.

"As the first book in the series, Harry Potter and the Philosopher's Stone has a special place in the affections of the millions of readers across the world and the proof reading error about the wand in the first edition has, of course, become a treasured piece of Harry Potter arcana. Like most enduring books aimed at younger readers, the Harry Potter books also have wide appeal to adults and there is a strong market among collectors for first editions. This copy is in excellent condition – one of the very best I've seen – and we're expecting a lot of interest," Bonhams Head of Books and Manuscripts, Matthew Haley, has said.

Now, where did we put our copy...?