diff --git a/Python/initconfig.c b/Python/initconfig.c
index a41a329..a30fdd1 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -80,6 +80,7 @@
 "PYTHONHOME   : alternate <prefix> directory (or <prefix>%lc<exec_prefix>).\n"
 "               The default module search path uses %s.\n"
 "PYTHONCASEOK : ignore case in 'import' statements (Windows).\n"
+"PYTHONUTF8: if set to 1, enable the UTF-8 mode.\n"
 "PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.\n"
 "PYTHONFAULTHANDLER: dump the Python traceback on fatal errors.\n";
 static const char usage_6[] =