diff --git a/application/migrations/227_extend_sig_info.php b/application/migrations/227_extend_sig_info.php
index 17d10aaff..654ad9745 100644
--- a/application/migrations/227_extend_sig_info.php
+++ b/application/migrations/227_extend_sig_info.php
@@ -4,6 +4,7 @@ class Migration_extend_sig_info  extends CI_Migration
 {
 
 	public function up() {
+		$this->db->query("ALTER TABLE ".$this->config->item('table_name')." CHANGE COLUMN COL_SIG COL_SIG VARCHAR(64) NULL DEFAULT NULL");
 		$this->db->query("ALTER TABLE ".$this->config->item('table_name')." CHANGE COLUMN COL_SIG_INFO COL_SIG_INFO VARCHAR(128) NULL DEFAULT NULL");
 		$this->db->query("ALTER TABLE ".$this->config->item('table_name')." CHANGE COLUMN COL_MY_SIG_INFO COL_MY_SIG_INFO VARCHAR(128) NULL DEFAULT NULL");
 		$this->db->query("ALTER TABLE ".$this->config->item('table_name')." CHANGE COLUMN COL_MY_SIG COL_MY_SIG VARCHAR(64) NULL DEFAULT NULL");