add <!DOCTYPE html>
diff --git a/system/index.html b/system/index.html
index c942a79..b702fbc 100644
--- a/system/index.html
+++ b/system/index.html
@@ -1,3 +1,4 @@
+<!DOCTYPE html>
 <html>
 <head>
 	<title>403 Forbidden</title>
@@ -7,4 +8,4 @@
 <p>Directory access is forbidden.</p>
 
 </body>
-</html>
\ No newline at end of file
+</html>