diff --git a/my-app/nginx.conf b/my-app/nginx.conf
index b5f85e7..28c8112 100644
--- a/my-app/nginx.conf
+++ b/my-app/nginx.conf
@@ -10,7 +10,8 @@ server {
 
     # Proxy REST API calls to the backend
     location /api {
-        proxy_pass ${BACKEND_URL};
+        set $backend_url ${BACKEND_URL};
+        proxy_pass $backend_url;
         proxy_http_version 1.1;
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
@@ -18,7 +19,8 @@ server {
 
     # Proxy Socket.IO (WebSocket + long-polling)
     location /socket.io {
-        proxy_pass ${BACKEND_URL};
+        set $backend_url ${BACKEND_URL};
+        proxy_pass $backend_url;
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection "upgrade";