--keyspace Not Working?

Hello all,

I have been trying for quite a while now to get --keyspace to work and cannot find any documentation on why it would not. I am trying to run this:


./hashcat64.exe hashes.txt -m 0 -w 3 -O -a 3 ?a?a?a?a?a?a?a?a --keyspace

and it repeatedly gives the usage message.

Thanks in advance!