diff --git a/xinclude.c b/xinclude.c
index 7fbcaca..1e96fe9 100644
--- a/xinclude.c
+++ b/xinclude.c
@@ -32,6 +32,7 @@
 
 #define XINCLUDE_NS (const xmlChar *) "http://www.w3.org/2001/XInclude"
 #define XINCLUDE_NODE (const xmlChar *) "include"
+#define XINCLUDE_FALLBACK (const xmlChar *) "fallback"
 #define XINCLUDE_HREF (const xmlChar *) "href"
 #define XINCLUDE_PARSE (const xmlChar *) "parse"
 #define XINCLUDE_PARSE_XML (const xmlChar *) "xml"