diff --git a/db/upgrade.php b/db/upgrade.php
new file mode 100644
index 0000000..6167b57
--- /dev/null
+++ b/db/upgrade.php
@@ -0,0 +1,59 @@
+<?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/>.
+
+/**
+ * @package   plagiarism_pchkorg
+ * @category  plagiarism
+ * @copyright PlagiarismCheck.org, https://plagiarismcheck.org/
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+function xmldb_plagiarism_pchkorg_upgrade($oldversion) {
+    global $DB;
+
+    $dbman = $DB->get_manager();
+
+
+    if ($oldversion < 2021072801) {
+
+        $table = new xmldb_table('plagiarism_pchkorg_files');
+
+        $field1 = new xmldb_field('signature', XMLDB_TYPE_CHAR, '40', null, null, null, null, null);
+        $field1->setComment('Signature');
+
+        $field2 = new xmldb_field('attempt', XMLDB_TYPE_INTEGER, '5', null, null, null, 0, null);
+        $field2->setComment('Sending attempts');
+
+        $field3 = new xmldb_field('itemid', XMLDB_TYPE_INTEGER, '10', null, null, null, null, null);
+        $field3->setComment('ID of file');
+
+        if (!$dbman->field_exists($table, $field1)) {
+            $dbman->add_field($table, $field1);
+        }
+
+        if (!$dbman->field_exists($table, $field2)) {
+            $dbman->add_field($table, $field2);
+        }
+
+        if (!$dbman->field_exists($table, $field3)) {
+            $dbman->add_field($table, $field3);
+        }
+
+        upgrade_plugin_savepoint(true, 2021072801, 'plagiarism', 'pchkorg');
+    }
+}
diff --git a/version.php b/version.php
index 3e4797f..8d6fb29 100644
--- a/version.php
+++ b/version.php
@@ -26,9 +26,9 @@ defined('MOODLE_INTERNAL') || die();
 if (!isset($plugin)) {
     $plugin = new stdClass();
 }
-$plugin->version = 2019052701;
+$plugin->version = 2021072801;
 $plugin->requires = 2017051500; // Requires Moodle 3.3 .
-$plugin->release = 'v3.6.1';
+$plugin->release = 'v3.6.2';
 $plugin->maturity = MATURITY_STABLE;
 $plugin->component = 'plagiarism_pchkorg';
 $plugin->dependencies = array(