Additional Include Directories not working with ".h" but are working with ".cpp"

Here is my folder structure:

/*
root/folderA/file_one.h
root/folderA/file_one.cpp
root/folderB/file_two.h
root/folderB/file_two.cpp
*/

I have my additional include directories set to the root directory.

The following include works fine in "file_two.cpp" but does not comipile in "file_two.h":

#include "folderA/file_one.h"

Any help would be greatly appreciated.