diff --git a/DOCBparser.c b/DOCBparser.c
index 0b4012a..3670c5a 100644
--- a/DOCBparser.c
+++ b/DOCBparser.c
@@ -10,6 +10,7 @@
  * daniel@veillard.com
  */
 
+#define IN_LIBXML
 #include "libxml.h"
 #ifdef LIBXML_DOCB_ENABLED