Can't use intrinsic MAX with more than 9 arguments

I've found that if I have overloaded the intrinsic MAX function with any arbitrary function, I am no longer able to use the intrinsic MAX function with 10 or more arguments, but it still works for 2 to 9 arguments.

For a simple example consider a program that simply attempts to call the intrinsic MAX function twice, once with 9 arguments and once with 10 arguments. Now, assume we have a module max_mod that overloads the intrinsic MAX function with a dummy function that accepts a single integer input and returns it. If I modify the original program to add a USE max_mod statement it will no longer compile. Code for this example is below:

program prog1
    implicit none
    real :: a
    a = max(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0)
    write (*, *) 'max of 9 numbers, expecting 9: ', a
    a = max(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0)
    write (*, *) 'max of 10 numbers, expecting 10: ', a
end program

This program compiles and works as expected. Next the module and the program using it:

module max_mod
    implicit none
    interface max
        module procedure max_dummy
    end interface max
contains
    function max_dummy (i)
        integer, intent(in) :: i
        integer :: max_dummy
        max_dummy = i
    end function max_dummy
end module max_mod

program prog2
    use max_mod
    implicit none
    real :: a
    a = max(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0)
    write (*, *) 'max of 9 numbers, expecting 9: ', a
    a = max(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0)
    write (*, *) 'max of 10 numbers, expecting 10: ', a
end program

This program will not compile, giving the error message

prog2.f90(20): error #6284: There is no matching specific function for this generic function reference.   [MAX]
    a = max(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0)
--------^
compilation aborted for prog2.f90 (code 1)

I found it odd that there is no error when only 9 arguments are specified, but for 10 or more I see this compilation error. I had expected this to compile. Am I misunderstanding something or is this a bug?

I'm using Intel Fortran ifort (IFORT) 15.0.2 20150121. I have also tested with 14.0.0 20130728 and 12.0.0 20101006.