diff --git a/.travis.yml b/.travis.yml
index 4325608..1b1fde6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -21,7 +21,7 @@ before_install:
                 ) ENGINE = INNODB DEFAULT CHARSET = utf8 ;
                 CREATE TABLE `user2` (
                   `id` BIGINT (20) NOT NULL AUTO_INCREMENT,
-                  `oid` BIGINT (20) NOT NULL DEFAULT '0',
+                  `oid` BIGINT (20) UNSIGNED NOT NULL DEFAULT '0',
                   `name` VARCHAR (20) DEFAULT NULL,
                   `sex` TINYINT (1) NOT NULL DEFAULT '0',
                   `age` SMALLINT (1) NOT NULL DEFAULT '0',