diff --git a/admin/roles/classes/admins_existing_selector.php b/admin/roles/classes/admins_existing_selector.php
index bae7b82cac6..7c51db6efb9 100644
--- a/admin/roles/classes/admins_existing_selector.php
+++ b/admin/roles/classes/admins_existing_selector.php
@@ -38,24 +38,28 @@ class core_role_admins_existing_selector extends user_selector_base {
             $name = 'removeselect';
         }
         $options['multiselect'] = false;
+        $options['includecustomfields'] = true;
         parent::__construct($name, $options);
     }
 
     public function find_users($search) {
         global $DB, $CFG;
-        list($wherecondition, $params) = $this->search_sql($search, '');
 
-        $fields      = 'SELECT ' . $this->required_fields_sql('');
+        [$wherecondition, $params] = $this->search_sql($search, 'u');
+        $params = array_merge($params, $this->userfieldsparams);
+
+        $fields = 'SELECT u.id, ' . $this->userfieldsselects;
 
         if ($wherecondition) {
-            $wherecondition = "$wherecondition AND id IN ($CFG->siteadmins)";
+            $wherecondition = "$wherecondition AND u.id IN ($CFG->siteadmins)";
         } else {
-            $wherecondition = "id IN ($CFG->siteadmins)";
+            $wherecondition = "u.id IN ($CFG->siteadmins)";
         }
-        $sql = " FROM {user}
+        $sql = " FROM {user} u
+                      $this->userfieldsjoin
                 WHERE $wherecondition";
 
-        list($sort, $sortparams) = users_order_by_sql('', $search, $this->accesscontext);
+        [$sort, $sortparams] = users_order_by_sql('u', $search, $this->accesscontext, $this->userfieldsmappings);
         $params = array_merge($params, $sortparams);
 
         // Sort first by email domain and then by normal name order.
diff --git a/admin/roles/classes/admins_potential_selector.php b/admin/roles/classes/admins_potential_selector.php
index f80295daddf..9d44cad91fa 100644
--- a/admin/roles/classes/admins_potential_selector.php
+++ b/admin/roles/classes/admins_potential_selector.php
@@ -39,24 +39,28 @@ class core_role_admins_potential_selector extends user_selector_base {
             $name = 'addselect';
         }
         $options['multiselect'] = false;
+        $options['includecustomfields'] = true;
         $options['exclude'] = explode(',', $CFG->siteadmins);
         parent::__construct($name, $options);
     }
 
     public function find_users($search) {
         global $CFG, $DB;
-        list($wherecondition, $params) = $this->search_sql($search, '');
 
-        $fields      = 'SELECT ' . $this->required_fields_sql('');
+        [$wherecondition, $params] = $this->search_sql($search, 'u');
+        $params = array_merge($params, $this->userfieldsparams);
+
+        $fields = 'SELECT u.id, ' . $this->userfieldsselects;
         $countfields = 'SELECT COUNT(1)';
 
-        $sql = " FROM {user}
+        $sql = " FROM {user} u
+                      $this->userfieldsjoin
                 WHERE $wherecondition AND mnethostid = :localmnet";
 
         // It could be dangerous to make remote users admins and also this could lead to other problems.
         $params['localmnet'] = $CFG->mnet_localhost_id;
 
-        list($sort, $sortparams) = users_order_by_sql('', $search, $this->accesscontext);
+        [$sort, $sortparams] = users_order_by_sql('u', $search, $this->accesscontext, $this->userfieldsmappings);
         $order = ' ORDER BY ' . $sort;
 
         // Check to see if there are too many to show sensibly.