Error using MARK

[cookie <cookie@xxxxxxxxxxxx>]

Hello-
  Can anyone tell me the error of my ways using

/sbin/iptables -v -t mangle -I SHAPER -p tcp --sport 8118 -j MARK -- 
set-mark 0x14
MARK  tcp opt -- in * out *  0.0.0.0/0  -> 0.0.0.0/0  tcp spt:8118  
MARK set 0x14
iptables: Invalid argument

I was sure that I had the correct syntax, but it keeps coming up  
Invalid argument.
Thanks
Brian