diff --git a/doc/ref/gh.texi b/doc/ref/gh.texi
index c28cf0825..ec94fbee7 100644
--- a/doc/ref/gh.texi
+++ b/doc/ref/gh.texi
@@ -925,7 +925,7 @@ Use @code{scm_from_locale_stringn} instead.
 Use @code{scm_from_locale_string} instead.
 
 @item @code{gh_set_substr}
-No direct scm equivalent.  [FIXME]
+Use @code{scm_string_copy_x}.
 
 @item @code{gh_symbol2scm}
 Use @code{scm_from_locale_symbol} instead.