Hi, The following MWE shows two LuaTeX-specific issues: * It does not print the primitive name "\write" * Tiny typo: double apostrophes in the word "didn''t" ===== \nonstopmode \outer\def\F{hoge} \immediate\write-1{\F}% => looks wrong % ! Forbidden control sequence found while scanning text of \ . \message{\F}% => OK % ! Forbidden control sequence found while scanning text of \message. \par\spacefactor\relax% The log file contains % "I'll just pretend that you didn''t ask for it." \bye ===== Best, Hironobu Yamashita