pt-online-schema-change loses foreign keys

The use of CREATE TABLE LIKE is causing foreign keys to disappear.

Before:

CREATE TABLE `film_actor` (
  `actor_id` smallint(5) unsigned NOT NULL,
  `film_id` smallint(5) unsigned NOT NULL,
  `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`actor_id`,`film_id`),
  KEY `idx_fk_film_id` (`film_id`),
  CONSTRAINT `fk_film_actor_actor` FOREIGN KEY (`actor_id`) REFERENCES `actor` (`actor_id`) ON UPDATE CASCADE,
  CONSTRAINT `fk_film_actor_film` FOREIGN KEY (`film_id`) REFERENCES `film` (`film_id`) ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

After:

CREATE TABLE `film_actor` (
  `actor_id` smallint(5) unsigned NOT NULL,
  `film_id` smallint(5) unsigned NOT NULL,
  `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `baron` int(11) DEFAULT NULL,
  PRIMARY KEY (`actor_id`,`film_id`),
  KEY `idx_fk_film_id` (`film_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

I believe that the solution needs to be retrieving the SHOW CREATE and sending it back to the server again with a different name.