I've added a directory to my cocoa project in XCode and moved a group of files into this directory since they all serve a specific purpose. The problem is when I compile it, some of the classes names in one of my controllers results in 'undefined symbols'. This all used to compile fine. Do I need to do something more than just prepend the included header path with the directory name in my source files? I've tried putting the directory path in project settings include paths, but, they still don't compile.