clusterssh: pass ssh options

clusterssh (cssh) can pass options to ssh: cssh -o "-o ConnectTimeout=1" myserver.mydomain.org I am trying to pass ProxyCommand option to ssh, but it does not work. With plain ssh, I can use this: ssh -o ProxyCommand='ssh root@1.2.3.4 nc %h %p' behind-fw.mydomain.org which will connect to server non-routable.mydomain.org via 1.2.3.4. But when I try to use this with cssh: cssh -o "-o ProxyCommand='ssh root@1.2.3.4 nc %h %p'" non-routable.mydomain.org I get this error: Cannot open pipe for reading when talking to non-routable.mydomain.org : Interrupted system call How can I pass ProxyCommand to cssh ?