diff --git a/portfolio/boxnet/db/upgrade.php b/portfolio/boxnet/db/upgrade.php
new file mode 100644
index 00000000000..b3422796f73
--- /dev/null
+++ b/portfolio/boxnet/db/upgrade.php
@@ -0,0 +1,50 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Upgrade.
+ *
+ * @package    portfolio_boxnet
+ * @copyright  2013 Frédéric Massart
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Upgrade function.
+ *
+ * @param int $oldversion the version we are upgrading from.
+ * @return bool result
+ */
+function xmldb_portfolio_boxnet_upgrade($oldversion) {
+    global $CFG, $DB;
+    require_once($CFG->dirroot . '/portfolio/boxnet/db/upgradelib.php');
+
+    $dbman = $DB->get_manager();
+
+    if ($oldversion < 2013050101) {
+        // Message the admins.
+        $existing = $DB->get_record('portfolio_instance', array('plugin' => 'boxnet'), '*', IGNORE_MULTIPLE);
+        if ($existing) {
+            portfolio_boxnet_admin_upgrade_notification();
+        }
+
+        upgrade_plugin_savepoint(true, 2013050101, 'portfolio', 'boxnet');
+    }
+
+    return true;
+}
diff --git a/portfolio/boxnet/db/upgradelib.php b/portfolio/boxnet/db/upgradelib.php
new file mode 100644
index 00000000000..fe87bd6cbf7
--- /dev/null
+++ b/portfolio/boxnet/db/upgradelib.php
@@ -0,0 +1,55 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Locallib.
+ *
+ * @package    portfolio_boxnet
+ * @copyright  2013 Frédéric Massart
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Send a message to the admin in regard with the APIv1 migration.
+ *
+ * @return void
+ */
+function portfolio_boxnet_admin_upgrade_notification() {
+    $admins = get_admins();
+
+    if (empty($admins)) {
+        return;
+    }
+    $a = new stdClass();
+    $a->docsurl = get_docs_url('Box.net_APIv1_migration');
+
+    foreach ($admins as $admin) {
+        $message = new stdClass();
+        $message->component         = 'moodle';
+        $message->name              = 'notices';
+        $message->userfrom          = get_admin();
+        $message->userto            = $admin;
+        $message->smallmessage      = get_string('apiv1migration_message_small', 'portfolio_boxnet');
+        $message->subject           = get_string('apiv1migration_message_subject', 'portfolio_boxnet');
+        $message->fullmessage       = get_string('apiv1migration_message_content', 'portfolio_boxnet', $a);
+        $message->fullmessagehtml   = get_string('apiv1migration_message_content', 'portfolio_boxnet', $a);
+        $message->fullmessageformat = FORMAT_PLAIN;
+        $message->notification      = 1;
+        message_send($message);
+    }
+}
diff --git a/portfolio/boxnet/lang/en/portfolio_boxnet.php b/portfolio/boxnet/lang/en/portfolio_boxnet.php
index b4e2c1ae7c4..a77bb6fac8a 100644
--- a/portfolio/boxnet/lang/en/portfolio_boxnet.php
+++ b/portfolio/boxnet/lang/en/portfolio_boxnet.php
@@ -23,6 +23,9 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+$string['apiv1migration_message_content'] = 'As part of the recent Moodle upgrade to 2.5.3, the Box.net portfolio plugin has been disabled. To re-enable it, you need to re-configure it as described in the documentation {$a->docsurl}.';
+$string['apiv1migration_message_small'] = 'This plugin has been disabled, as it requires configuration as described in the documentation Box.net APIv1 migration.';
+$string['apiv1migration_message_subject'] = 'Important information regarding Box.net portfolio plugin';
 $string['clientid'] = 'Client ID';
 $string['clientsecret'] = 'Client secret';
 $string['existingfolder'] = 'Existing folder to put file(s) into';
diff --git a/portfolio/boxnet/version.php b/portfolio/boxnet/version.php
index f5091c50370..e14ebf8b4b3 100644
--- a/portfolio/boxnet/version.php
+++ b/portfolio/boxnet/version.php
@@ -24,7 +24,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2013050100;        // The current plugin version (Date: YYYYMMDDXX)
+$plugin->version   = 2013050101;        // The current plugin version (Date: YYYYMMDDXX)
 $plugin->requires  = 2013050100;        // Requires this Moodle version
 $plugin->component = 'portfolio_boxnet'; // Full name of the plugin (used for diagnostics)
 $plugin->cron      = 0;