We have made two changes to the way that our TLS-ALPN-01 challenge validation works. These changes will only affect clients that specifically use TLS-ALPN-01; for example, it is not a default choice in Certbot. First, we now guarantee that our client which reaches out to conduct the “acme-tls/1” handshake will negotiate TLS version 1.2 or higher. If your ACME client or integration only supports a