"A reference to a volatile field will not be treated as volatile" implications

The following code

using System.Threading;class Test{    volatile int counter = 0;    public void Increment()    {        Interlocked.Increment(ref counter);    }}

Raises the following compiler warning:

"A reference to a volatile field will not be treated as volatile"

Am I doing something wrong here to raise this warning? Why does the compiler me warn about this?