i2pd: nc: connection failed, unsupported address type

Trying to get ssh working on top of i2p.

Server

i2pd.conf

log = syslog
loglevel = error
notransit = true

[http]
enabled = false

[socksproxy]
enabled = false

[httpproxy]
enabled = false

[sam]
enabled = false

tunnels.conf

[ssh]
type = server
host = 127.0.0.1
port = 22
keys = ssh-privkey.dat

Client

i2pd.conf

log = syslog
loglevel = error
notransit = true

[http]
enabled = false

[httpproxy]
enabled = false

[sam]
enabled = false

tunnels.conf

The file is empty.

.ssh/config

Host example
        HostName xxx.b32.i2p
        Port 22
        ProxyCommand nc -X 5 -x 127.0.0.1:4447 %h %p

Error message on the client:

$ ssh example
nc: connection failed, unsupported address type
ssh_exchange_identification: Connection closed by remote host

The very same ProxyCommand configuration (except the port, obviously) works just fine with Tor. Also, I’m sure i2p works too because curl works:

$ curl --socks5-hostname 127.0.0.1:4447 xxx.b32.i2p:22
SSH-2.0-OpenSSH_7.9
Protocol mismatch.

So this might be something that dissatisfies nc.

Could you please suggest on how to make ssh+nc working in this case?

Thanks.