diff --git a/src/mysql.cpp b/src/mysql.cpp
index 68bcf51..d4d0626 100644
--- a/src/mysql.cpp
+++ b/src/mysql.cpp
@@ -818,6 +818,7 @@ void module::mysql_conn::regist(sol::state* lua)
 {
     lua->new_usertype<module::mysql_conn>("fw_mysql_conn",
         "new", sol::constructors<module::mysql_conn(), module::mysql_conn(ylib::mysql::conn*)>(),
+        sol::base_classes, sol::bases<module::base>(),
         "begin", &module::mysql_conn::begin,
         "clear", &module::mysql_conn::clear,
         "commit", &module::mysql_conn::commit,