diff --git a/modules/Migration/schema/811_to_812.php b/modules/Migration/schema/811_to_812.php
new file mode 100644
index 0000000000000000000000000000000000000000..ce3d884a1435a5a7bb19c37acf699bb5adcb6944
--- /dev/null
+++ b/modules/Migration/schema/811_to_812.php
@@ -0,0 +1,16 @@
+<?php
+if (defined('VTIGER_UPGRADE')) {
+ini_set('error_reporting', E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT & ~E_WARNING);
+ini_set('display_errors', 'On');
+include_once 'include/utils/utils.php';
+include_once 'includes/runtime/Viewer.php';
+include_once 'includes/runtime/LanguageHandler.php';
+$db = PearDatabase::getInstance();
+global $current_user;
+$current_user = Users::getActiveAdminUser();
+$db->pquery('DELETE detail FROM vtiger_modtracker_detail AS detail 
+                LEFT JOIN vtiger_modtracker_basic AS basic ON detail.id = basic.id WHERE basic.id IS NULL');
+
+$db->pquery('ALTER TABLE vtiger_modtracker_detail ADD CONSTRAINT fk_modtracker_basic_id FOREIGN KEY (id) REFERENCES vtiger_modtracker_basic(id) ON DELETE CASCADE');
+
+}
\ No newline at end of file