It would be best if the ISO_Fortran_binding.h file that we expose to C/C++ compilation be self-contained. Maybe the dependence on api-attrs.h can be made conditional and off by default. Or the inclusion of api-attrs.h moved to a wrapper header that appears only in the library, with the exposed ISO_Fortran_binding.h file containing only some empty #defines for the API macros that get activated when the wrapper hasn’t defined them. Please check with Slava, he made this change.