I'm trying to set some WiredTiger options on the command line when starting a mongoD along the lines of:

mongod --syslog --shardsvr --storageEngine wiredTiger --wiredTigerCacheSizeGB X --wiredTigerEngineConfig="eviction_target=X" --replSet X --dbpath X --port X

It is giving the error:

Error parsing command line: unknown option wiredTigerEngineConfig

Looking at the docs, this seems like a supported option: http://docs.mongodb.org/manual/reference/parameters/

Am I doing something wrong? I have tried with both mongoD version 3.0.5 and 3.0.6.