diff --git a/CHANGES.md b/CHANGES.md
index b793fa8..907d930 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 Note - All hash comments refer to the issue number. Eg. #169 refers to https://github.com/mdjnelson/moodle-mod_customcert/issues/169.
 
+## [3.11.1] - 2021-XX-YY
+
+### Fixed
+- Usage of deprecated functions (#423)
+
 ## [3.10.1] - 2021-XX-YY
 
 ### Added
diff --git a/classes/certificate.php b/classes/certificate.php
index bbc633f..44b3d4e 100644
--- a/classes/certificate.php
+++ b/classes/certificate.php
@@ -270,8 +270,11 @@ class certificate {
         $allparams = $conditionsparams + array('customcertid' => $customcertid);
 
         // Return the issues.
-        $extrafields = get_extra_user_fields(\context_module::instance($cm->id));
-        $ufields = \user_picture::fields('u', $extrafields);
+        $context = \context_module::instance($cm->id);
+        $extrafields = \core_user\fields::for_identity($context)->get_required_fields();
+
+        $ufields = \core_user\fields::for_userpic()->including(...$extrafields);
+        $ufields = $ufields->get_sql('u', false, '','', false)->selects;
         $sql = "SELECT $ufields, ci.id as issueid, ci.code, ci.timecreated
                   FROM {user} u
             INNER JOIN {customcert_issues} ci
diff --git a/classes/report_table.php b/classes/report_table.php
index fd5c4ab..40cc4ab 100644
--- a/classes/report_table.php
+++ b/classes/report_table.php
@@ -66,7 +66,7 @@ class report_table extends \table_sql {
         parent::__construct('mod_customcert_report_table');
 
         $context = \context_module::instance($cm->id);
-        $extrafields = get_extra_user_fields($context);
+        $extrafields = \core_user\fields::for_identity($context)->get_required_fields();
 
         $columns = [];
         $columns[] = 'fullname';
@@ -79,7 +79,7 @@ class report_table extends \table_sql {
         $headers = [];
         $headers[] = get_string('fullname');
         foreach ($extrafields as $extrafield) {
-            $headers[] = get_user_field_name($extrafield);
+            $headers[] = \core_user\fields::get_display_name($extrafield);
         }
         $headers[] = get_string('receiveddate', 'customcert');
         $headers[] = get_string('code', 'customcert');
diff --git a/element/userfield/classes/element.php b/element/userfield/classes/element.php
index 63f4bf2..d4fb6e5 100644
--- a/element/userfield/classes/element.php
+++ b/element/userfield/classes/element.php
@@ -24,6 +24,8 @@
 
 namespace customcertelement_userfield;
 
+use core_user\fields;
+
 defined('MOODLE_INTERNAL') || die();
 
 /**
@@ -43,24 +45,24 @@ class element extends \mod_customcert\element {
     public function render_form_elements($mform) {
         // Get the user profile fields.
         $userfields = array(
-            'firstname' => get_user_field_name('firstname'),
-            'lastname' => get_user_field_name('lastname'),
-            'username' => get_user_field_name('username'),
-            'email' => get_user_field_name('email'),
-            'city' => get_user_field_name('city'),
-            'country' => get_user_field_name('country'),
-            'url' => get_user_field_name('url'),
-            'icq' => get_user_field_name('icq'),
-            'skype' => get_user_field_name('skype'),
-            'aim' => get_user_field_name('aim'),
-            'yahoo' => get_user_field_name('yahoo'),
-            'msn' => get_user_field_name('msn'),
-            'idnumber' => get_user_field_name('idnumber'),
-            'institution' => get_user_field_name('institution'),
-            'department' => get_user_field_name('department'),
-            'phone1' => get_user_field_name('phone1'),
-            'phone2' => get_user_field_name('phone2'),
-            'address' => get_user_field_name('address')
+            'firstname' => fields::get_display_name('firstname'),
+            'lastname' => fields::get_display_name('lastname'),
+            'username' => fields::get_display_name('username'),
+            'email' => fields::get_display_name('email'),
+            'city' => fields::get_display_name('city'),
+            'country' => fields::get_display_name('country'),
+            'url' => fields::get_display_name('url'),
+            'icq' => fields::get_display_name('icq'),
+            'skype' => fields::get_display_name('skype'),
+            'aim' => fields::get_display_name('aim'),
+            'yahoo' => fields::get_display_name('yahoo'),
+            'msn' => fields::get_display_name('msn'),
+            'idnumber' => fields::get_display_name('idnumber'),
+            'institution' => fields::get_display_name('institution'),
+            'department' => fields::get_display_name('department'),
+            'phone1' => fields::get_display_name('phone1'),
+            'phone2' => fields::get_display_name('phone2'),
+            'address' => fields::get_display_name('address')
         );
         // Get the user custom fields.
         $arrcustomfields = \availability_profile\condition::get_custom_profile_fields();