diff --git a/draft-ietf-tls-rfc8446bis.md b/draft-ietf-tls-rfc8446bis.md
index 13c3d331..edc461bc 100644
--- a/draft-ietf-tls-rfc8446bis.md
+++ b/draft-ietf-tls-rfc8446bis.md
@@ -1283,7 +1283,8 @@ processed and transmitted as specified by the current active connection state.
        } Handshake;
 
 Protocol messages MUST be sent in the order defined in
-{{the-transcript-hash}} and shown in the diagrams in {{protocol-overview}}.
+{{the-transcript-hash}} and shown in the diagrams in {{protocol-overview}},
+unless modified by a TLS extension.
 A peer which receives a handshake message in an unexpected order
 MUST abort the handshake with an "unexpected_message" alert.