Can't seem to get includes to work using pkg-config on windows due to space in "Program Files" dir

I have one library project that I aim to use with a second project.

In the library project, I have set the install prefix to 'C:/Program Files/libname/'

I generate a pkg-config file using the pkg.generate() function and this goes well.

However on my second project, I have errors with the include step.

cl : Command line warning D9024 : unrecognized source file type 'Files/libname/include', object file assumed

It appears that the space in the word Program Files isn't being handled.