diff --git a/docs/document/level-0/ch07-xray-server.md b/docs/document/level-0/ch07-xray-server.md
index 46351a0..a4eea54 100644
--- a/docs/document/level-0/ch07-xray-server.md
+++ b/docs/document/level-0/ch07-xray-server.md
@@ -279,6 +279,7 @@
             "network": "tcp",
             "security": "tls",
             "tlsSettings": {
+              "alpn": "http/1.1",
               "certificates": [
                 {
                   "certificateFile": "/home/vpsadmin/xray_cert/xray.crt",