diff --git a/config/config.sh b/config/config.sh
index fb2fe5c..1c316b1 100644
--- a/config/config.sh
+++ b/config/config.sh
@@ -35,9 +35,9 @@ server {
     location /novnc/websockify {
       proxy_pass http://127.0.0.1:6080/;
       proxy_http_version 1.1;
-      proxy_set_header Upgrade $http_upgrade;
+      proxy_set_header Upgrade \$http_upgrade;
       proxy_set_header Connection "Upgrade";
-      proxy_set_header Host $host;
+      proxy_set_header Host \$host;
     }
 
     location / {