Safari adding .html to download

Question

I have a little function, that creates .xls document(using PHPexcel) and then sends it to php://output. Then user download it.
Everything works fine, except that safari on

Answer 1

If someone is still facing above problem

Please change content type as

header('Content-type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');