diff --git a/plugins/OStatus/lib/xrd.php b/plugins/OStatus/lib/xrd.php
index f00e1f8096..aa13ef0242 100644
--- a/plugins/OStatus/lib/xrd.php
+++ b/plugins/OStatus/lib/xrd.php
@@ -57,6 +57,9 @@ class XRD
             throw new Exception("Invalid XML");
         }
         $xrd_element = $dom->getElementsByTagName('XRD')->item(0);
+        if (!$xrd_element) {
+            throw new Exception("Invalid XML, missing XRD root");
+        }
 
         // Check for host-meta host
         $host = $xrd_element->getElementsByTagName('Host')->item(0);