diff --git a/nginx-template.conf b/nginx-template.conf
index 57f3a5c..dfce65d 100644
--- a/nginx-template.conf
+++ b/nginx-template.conf
@@ -11,7 +11,7 @@ server {
 
     # Proxy API requests to the backend server
     location /api/ {
-        proxy_pass http://$BACKEND_HOST:$BACKEND_PORT/;
+        proxy_pass http://${BACKEND_HOST}:${BACKEND_PORT}/;
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection 'upgrade';