Support ALGORITHM=/LOCK= syntax for CREATE/DROP INDEX

I used MariaDB as alternative to a MySQL-Server. For a software-package I have to make updates for an existing database with prepared sql-files.

After an update from mariadb 5 to mariadb 10.1 can use ALGRITHM in CREATE INDEX - queries. But the DROP INDEX - queries (DROP INDEX name ON tbl ALGORITHM = INPLACE LOCK = NONE;) dies with following Message:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ALGORITHM = INPLACE LOCK = NONE' at line 3;

The message is the same errormessage, which I have in mariaDB 5 for my CREATE INDEX ..., ALGORITHM = INPLACE, LOCK = NONE;. So it seems, that the documented ALGORITHM-Function isn't implemented yet?