J.K. Rowling’s phenomenally popular tales of a boy’s adventures at Hogwarts School of Witchcraft and Wizardry continue to have legs in any format. Just four months after the Harry Potter digital audiobooks became available via subscription-based Audible, the company reports that one million total units have been sold via audible.com, audible.co.uk, audible.de and audible.com.au since the titles’ official release on November 20, 2015.

“We’re gratified that the series has picked up steam so quickly on Audible, and look forward to bringing even more listeners to J.K. Rowling’s richly imagined universe through our affordable platform,” said chief content officer Andy Gaies in a statement. While Audible is the only subscription service to offer the digital audio series, listeners can still download the Harry Potter digital audiobook editions via Pottermore, Rowling’s website/company that remains the global publisher of the Harry Potter digital audiobooks and e-books.

Susan L. Jurevics, CEO of Pottermore, offered this statement about the new sales tally: “The Harry Potter digital audiobooks are now more accessible thanks to Audible’s ability to successfully connect with its vast membership base. We look forward to growing the audience with Audible and helping more users experience the joys and magic of J.K. Rowling’s Wizarding World.”