diff --git a/bundles/org.openhab.core.io.http.auth/pages/authorize.html b/bundles/org.openhab.core.io.http.auth/pages/authorize.html
index 9b24fe84e..691d50ad0 100644
--- a/bundles/org.openhab.core.io.http.auth/pages/authorize.html
+++ b/bundles/org.openhab.core.io.http.auth/pages/authorize.html
@@ -1,4 +1,4 @@
-<html>
+<!DOCTYPE html>
 <head>
 <title>openHAB</title>
 <meta charset="utf-8">
