How can I ignore an operator overload

I am implementing IComparible with

public int CompareTo(RangeEx range)
    if (range == null)
                return 1;
// more stuff

public static bool operator ==(RangeEx x, RangeEx y) { return x.CompareTo(y) == 0; }

The problem is the "if (range == null)" calls the operator overload. How can I do the check for null by not calling the overload?