--- doc/m4.texi.orig	2016-12-31 22:34:38 UTC
+++ doc/m4.texi
@@ -1,6 +1,7 @@
 \input texinfo @c -*- texinfo -*-
 @comment ========================================================
 @comment %**start of header
+@documentencoding ISO-8859-1
 @setfilename m4.info
 @include version.texi
 @settitle GNU M4 @value{VERSION} macro processor