diff --git a/admin/tool/brickfield/README.md b/admin/tool/brickfield/README.md
index d95a3294bc9..30c5bc13445 100644
--- a/admin/tool/brickfield/README.md
+++ b/admin/tool/brickfield/README.md
@@ -1,7 +1,23 @@
-# Accessibility plugin #
+# Brickfield accessibility tool plugin #
+
+Copyright (C) 2021 [Brickfield Education Labs](https://www.brickfield.ie/)
 
 The Accessibility admin tool plugin provides a simple means of checking content for any accessibility issues.
 
+Created by an enthusiastic team from Brickfield Education Labs, including:
+* Karen Holland
+* Gavin Henrick
+* Mike Churchward
+* Renée Mackey
+* Laia Joana Canet
+* Jay Churchward
+* Paul Ffrench
+* Holly Lynn
+* Michael Pound
+* Max Larkin
+
+with a little help from our friends.
+
 Portions of the htmlchecker files were derived from the ["Quail PHP Accessibility Library"](https://code.google.com/archive/p/quail-lib/).
 The Quail library (Copyright (C) 2009 Kevin Miller) is licensed under [GNU GPL v3](http://www.gnu.org/licenses/gpl.html).
 See the LICENSE_QUAIL.txt file in this directory for original Quail license information.
diff --git a/admin/tool/brickfield/classes/brickfieldconnect.php b/admin/tool/brickfield/classes/brickfieldconnect.php
index 4587dfe95cd..ee1857eb375 100644
--- a/admin/tool/brickfield/classes/brickfieldconnect.php
+++ b/admin/tool/brickfield/classes/brickfieldconnect.php
@@ -85,6 +85,12 @@ class brickfieldconnect extends curl {
         }
 
         $headers = $this->get_common_headers();
+
+        // Sanity-check $headers 'id' value.
+        if (!isset($headers['id'])) {
+            return false;
+        }
+
         $this->set_headers($headers);
         $summary = accessibility::get_summary_data($headers['id']);
         $body = json_encode($summary, JSON_UNESCAPED_SLASHES);
@@ -249,4 +255,4 @@ class brickfieldconnect extends curl {
             return self::$baseapiuri;
         }
     }
-}
\ No newline at end of file
+}