Why can't I pass autocheck?

MY CODE:

    def checkio(number):
    if number % 3 == 0 and number % 5 == 0:
        print "Fizz Buzz"
    elif number % 3 == 0:
        print "Fizz"
    elif number % 5 == 0:
        print "Buzz"
    else:
        print str(number)
    return str(number)

Autocheck says "Your result 15" but I checked with checkio(15) and it prints "Fizz Buzz"

PLease help.

Thankyou!