Bind 9.3.0 - Flushname NXDOMAIN

[Zain Al Abdeen]

After running rndc flushname for a cached NXDOMAIN, I still could see 
the record after dumping the cache. Whereas it works fine for exisiting 
records.

Is there an option to enable flushing of a non-existing name ?

Thanks & Regards,
--Zain