diff --git a/nginx.conf.template b/nginx.conf.template
index 0887be5..3197033 100644
--- a/nginx.conf.template
+++ b/nginx.conf.template
@@ -26,6 +26,6 @@ server {
         proxy_ssl_server_name on;
         proxy_set_header Host "esi.evetech.net";
         proxy_set_header X-Forwarded-Proto https;
-        proxy_set_header User-Agent $ESI_USER_AGENT;
+        proxy_set_header User-Agent "${ESI_USER_AGENT}";
     }
 }
\ No newline at end of file