Unknown rule HostSNI on tcp router

[splatadder]

Hi,

this is probably a configuration error, but I've been a couple of hours on it and can't find it..
I configured a tcp router, but it always errors out with:
unknown rule HostSNI

Configuration:

        - "traefik.enable=true"
        - "traefik.docker.network=backend"
        - "traefik.tcp.routers.front.entrypoints=front_test"
        - "traefik.tcp.routers.front.rule=HostSNI('host1','host2')"
#        - "traefik.tcp.routers.front.tls=true"
        - "traefik.tcp.routers.front.service=front"
        - "traefik.tcp.services.front.loadbalancer.server.port=999"

Does anyone have an ideia what could be wrong?

[splatadder]

Should have posted sooner...

I was using single quotes (´) instead of backticks ( `)...