Log DNS Queries

Hi,

I want to log all DNS queries on my MikroTikRouter (RouterOS v6.48 (stable)).
I found in all forums, etc… that this command will do it:

system logging add action=memory target=dns

but it does not work in my router. There comes always this error:

expected end of command (line 1 column 34)

What I’m doing wrong?

/system logging add action=memory topics=dns