diff --git a/docs/source/reference/config-proxy.md b/docs/source/reference/config-proxy.md
index 9e493cf4..b1baecf8 100644
--- a/docs/source/reference/config-proxy.md
+++ b/docs/source/reference/config-proxy.md
@@ -83,6 +83,7 @@ server {
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
 
         # websocket headers
+        proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection $connection_upgrade;