diff --git a/Documentation/Makefile.in b/Documentation/Makefile.in
index 0cc65398..d35cb858 100644
--- a/Documentation/Makefile.in
+++ b/Documentation/Makefile.in
@@ -66,7 +66,6 @@ ASCIIDOC_DEPS =
 endif
 
 MANPAGE_XSL = manpage-normal.xsl
-XMLTO_EXTRA =
 INSTALL = @INSTALL@
 RM = @RM@
 RMDIR = @RMDIR@