diff --git a/graph b/graph
index d3b9f13..f17c343 100755
--- a/graph
+++ b/graph
@@ -52,7 +52,7 @@ fi
 if [ -z "$graph" ]
 then
 	cat <<-EOHTML
-		content-type: text/html
+		content-type: application/xhtml+xml
 		Last-Modified: $(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z')
 		Expires: $(LC_ALL=C TZ=GMT date +'%a, %d %b %Y %X %Z' -d '10 minutes')
 		refresh: 600