diff --git a/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php b/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
index 33ae11397e5..4c3ce1758e0 100644
--- a/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
+++ b/lib/htmlpurifier/HTMLPurifier/Printer/ConfigForm.php
@@ -32,6 +32,11 @@ class HTMLPurifier_Printer_ConfigForm extends HTMLPurifier_Printer
      */
     protected $compress = false;
 
+    /**
+     * @var HTMLPurifier_Config
+     */
+    protected $genConfig;
+
     /**
      * @param string $name Form element name for directives to be stuffed into
      * @param string $doc_url String documentation URL, will have fragment tagged on
diff --git a/lib/htmlpurifier/readme_moodle.txt b/lib/htmlpurifier/readme_moodle.txt
index 59d0138a794..d58010fb93b 100644
--- a/lib/htmlpurifier/readme_moodle.txt
+++ b/lib/htmlpurifier/readme_moodle.txt
@@ -14,3 +14,7 @@ Description of HTML Purifier library import into Moodle
     HTMLPurifier.path.php
 * add locallib.php with Moodle specific extensions to /lib/htmlpurifier/
 * add this readme_moodle.txt to /lib/htmlpurifier/
+
+Local changes:
+* 2023-06-06 Applied patch https://github.com/ezyang/htmlpurifier/pull/346 to avoid PHP 8.2 deprecations.
+  See MDL-78143 for more details.
\ No newline at end of file