diff --git a/classes/admin/setting_idpmetadata.php b/classes/admin/setting_idpmetadata.php
index 2e5763158..404a2ddac 100644
--- a/classes/admin/setting_idpmetadata.php
+++ b/classes/admin/setting_idpmetadata.php
@@ -210,8 +210,20 @@ public function get_idps_data($value) {
      */
     private function get_idp_xml_path(idp_data $idp) {
         $xml = new DOMDocument();
-        if (!$xml->loadXML($idp->rawxml)) {
-            throw new setting_idpmetadata_exception(get_string('idpmetadata_invalid', 'auth_saml2'));
+
+        libxml_use_internal_errors(true);
+
+        $rawxml = $idp->rawxml;
+
+        if (!$xml->loadXML($rawxml)) {
+            $errors = libxml_get_errors();
+            $lines = explode("\n", $rawxml);
+            $msg = '';
+            foreach ($errors as $error) {
+                $msg .= "<br>Error ({$error->code}) line $error->line char  $error->column: $error->message";
+            }
+
+            throw new setting_idpmetadata_exception(get_string('idpmetadata_invalid', 'auth_saml2') . $msg);
         }
 
         $xpath = new DOMXPath($xml);
diff --git a/classes/idp_parser.php b/classes/idp_parser.php
index a38aa4c75..3cc0af958 100644
--- a/classes/idp_parser.php
+++ b/classes/idp_parser.php
@@ -56,7 +56,18 @@ public function parse($data) {
         return $this->idps;
     }
 
+    /**
+     * Does the field *look* like xml, mostly?
+     */
     public function check_xml($xml) {
+
+        $declaration = '<?xml';
+
+        $xml = trim($xml);
+        if (substr($xml, 0, strlen($declaration)) === $declaration) {
+            return true;
+        }
+
         libxml_use_internal_errors(true);
         if (simplexml_load_string($xml)) {
             return true;