This option is now available in docker-compose 1.10.0-rc1, you’ll need to upgrade to that version (pip install docker-compose==1.10.0-rc1) and also update your docker-compose.yml file to version 2.1 per docs
Example docker-compose.yml:
version: '2.1'
services:
app:
build: .
sysctls:
- net.ipv6.conf.all.disable_ipv6=1