https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58667
--- Comment #3 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- The gfortran documentation says -Wconversion Warn about implicit conversions that are likely to change the value of the expression after conversion. Implied by -Wall. -Wconversion-extra Warn about implicit conversions between different types and kinds. This option does not imply -Wconversion. Isn't it enough? Without feedback I'll close this PR as WONTFIX.