Is there a cleaner way to store fractional seconds in update times?

Percona 5.6.32 :
mysql> create table test0( -> id int(2) not null auto_increment, -> modified timestamp not null default current_timestamp on update current_timestamp, -> primary key (id) -> ); Query OK, 0 rows affected (0.01 sec) mysql> show create table test0\G *************************** 1. row *************************** Table: test0 Create Table: CREATE TABLE test0 ( id int(2) NOT NULL AUTO_INCREMENT, modified timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (id) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 1 row in set (0.00 sec)
so far so good. Now:
mysql> create table test1( -> id int(2) not null auto_increment, -> modified timestamp(2) not null default current_timestamp on update current_timestamp, -> primary key (id) -> ); ERROR 1067 (42000): Invalid default value for ‘modified’
What’s more, I can create the table with a timestamp(2) column, as long as I skip the defaults, and can create separate triggers to update that column on insert/udate, but adding the current_timestamp default just fails…