https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59997
--- Comment #7 from drikosev at otenet dot gr --- The option of omitting the trailing underscore (-fno-underscoring) is explained at https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html In the above link, there is also a wish (hope) that in future versions of GNU Fortran this issue will be improved. I guess the future is not here yet! So, the program seems to be ok. Regards, Ev. Drikos