diff --git a/badges/classes/form/external_backpack.php b/badges/classes/form/external_backpack.php
index b5d10e06cad..3d632760df8 100644
--- a/badges/classes/form/external_backpack.php
+++ b/badges/classes/form/external_backpack.php
@@ -56,12 +56,12 @@ class external_backpack extends \moodleform {
         $mform->addElement('text', 'backpackapiurl',  get_string('backpackapiurl', 'core_badges'));
         $mform->setType('backpackapiurl', PARAM_URL);
         $mform->addRule('backpackapiurl', null, 'required', null, 'client');
-        $mform->addRule('backpackapiurl', get_string('maximumchars', '', 255), 'maxlength', 50, 'client');
+        $mform->addRule('backpackapiurl', get_string('maximumchars', '', 255), 'maxlength', 255, 'client');
 
         $mform->addElement('text', 'backpackweburl', get_string('backpackweburl', 'core_badges'));
         $mform->setType('backpackweburl', PARAM_URL);
         $mform->addRule('backpackweburl', null, 'required', null, 'client');
-        $mform->addRule('backpackweburl', get_string('maximumchars', '', 255), 'maxlength', 50, 'client');
+        $mform->addRule('backpackweburl', get_string('maximumchars', '', 255), 'maxlength', 255, 'client');
 
         $apiversions = badges_get_badge_api_versions();
         $mform->addElement('select', 'apiversion', get_string('apiversion', 'core_badges'), $apiversions);