com - DllGetClassObject is not exported, (so is never called and interface is never found)

Question

I am trying to write a COM server and client. When I call CoCreateInstance(), COM Engine is expected to call DllGetClassObject(), but it seems it is never called(I have put simple message box before all other functionality, so I am sure it is not called).

On further inspection, I found that it is not exported. I tested it using Dumpbin /EXPORTS

My def file is

LIBRARY ClassFactoryServer
EXPORTS
    DllGetClassObject   @100     PRIVATE
    DllCanUnloadNow     @101     PRIVATE

I don't know why these are not exported. I can not use __declspec(dllexport) for known reason, there is other way of using #pragma but I am quite ready to write .def file, but don't know why functions are not getting exported.