Unknown option: --type for watchdog-delete

I am not sure if this is the same problem that was reported in http://drupal.org/node/1356666, but I am seeing the following in drush-6.x-dev (updated this morning via PEAR).

$ drush @mysite wd-del --type=php
Unknown option: --type.  See `drush help watchdog-delete` for available options. To suppress [error]
this error, add the option --strict=0.

$ drush help wd-del
Delete watchdog messages. Arguments or options must be provided to specify which messages to delete.

Examples:
 drush watchdog-delete all                 Delete all messages.
 drush watchdog-delete 64                  Delete messages with id 64.
 drush watchdog-delete "cron run           Delete messages containing the string "cron run succesful".
 succesful"
 drush watchdog-delete --severity=notice   Delete all messages with a severity of notice.
 drush watchdog-delete --type=cron         Delete all messages of type cron.


Arguments:
 severity                                  Delete messages of a given severity level.
 type                                      Delete messages of a given type.


Aliases: wd-del, wd-delete

$ drush --version
drush version 6.0-dev

Executing as

$ drush @mysitewd-del --type=php --strict=0

does behave as it should.