An easily missable typo in the first edition of JK Rowling's generation-ruling Harry Potter and the Philosopher's Stone novel is expected to fetch up to £20,000 at auction.

We'll give you all a second to frantically scramble towards your dusty living room bookshelves. There have been hundreds of millions of Harry Potter books sold since 1997, but if you're jammy enough to own one of 500 hardback copies of the original story then you could be sitting on a small fortune. As reported by The Sun, early editions of the book have a printing error on the 53rd page, which lists a number of items new students are expected to bring to Hogwarts. In this version of the book, you'll notice that "1 wand" is listed twice. Looking back on it now, Harry and pals could probably have done with a back-up wand or two, but it was definitely a mistake. https://twitter.com/danasclly/status/506488549576019969?ref_src=twsrc%5Etfw London's Bonhams Fine Books and Manuscripts are planning to sell one of the books in November for an extortionate sum. Bonhams’ Head of Books and Manuscripts Matthew Haley said: "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."