diff --git a/application/migrations/142_alter_lotw_user_table.php b/application/migrations/142_alter_lotw_user_table.php
new file mode 100644
index 00000000..95898297
--- /dev/null
+++ b/application/migrations/142_alter_lotw_user_table.php
@@ -0,0 +1,16 @@
+<?php
+
+defined('BASEPATH') OR exit('No direct script access allowed');
+
+class Migration_alter_lotw_user_table extends CI_Migration {
+
+	public function up() {
+		$this->db->query("ALTER TABLE lotw_users ADD UNIQUE INDEX callsign_UNIQUE (callsign ASC)");
+		$this->db->query("ALTER TABLE lotw_users DROP INDEX callsign");
+	}
+
+	public function down(){
+		$this->db->query("ALTER TABLE lotw_users DROP INDEX callsign_UNIQUE");
+		$this->db->query("ALTER TABLE lotw_users ADD INDEX callsign (callsign)");
+	}
+}