Allow ePub File Uploads

August 18, 2015

WordPress does not natively support uploads for ePub files.  To enable this support, add the following to functions.php

function addUploadMimes($mimes) {
    $mimes = array_merge($mimes, array(
        'epub|mobi' => 'application/octet-stream'
    ));
    return $mimes;
}
add_filter('upload_mimes', 'addUploadMimes');

Sourced here.