Unable to re-mount /proc in Proxmox 3 containers?

Recently I discovered that the default /proc mount inside CentOS containers running under Proxmox 3.1 were mounted insecurely:

# mount|grep " /proc"
proc on /proc type proc (rw,relatime)

Under older versions of Proxmox, I was able to correct this by running:

mount -o remount,nosuid,noexec /proc

However, when running under Proxmox 3.1, the above returns:

mount: mount failed

Anyone here aware of a fix for this?

Thanks,

Curtis