diff --git a/doc/comedilib.sgml b/doc/comedilib.sgml
index 788f970..2460940 100644
--- a/doc/comedilib.sgml
+++ b/doc/comedilib.sgml
@@ -1,4 +1,4 @@
-<!doctype linuxdoc system>
+<!doctype linuxdoc public "-//LinuxDoc//DTD LinuxDoc 96//EN">
 
 <article>
 <title>Comedi Documentation