diff --git a/nginx/start.sh b/nginx/start.sh
index a0f7718b..3f65b90c 100755
--- a/nginx/start.sh
+++ b/nginx/start.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-if [ -z ENABLE_CERTBOT ] || [ -f /certs/cert.pem ]
+if [ -z $ENABLE_CERTBOT ] || [ -f /certs/cert.pem ]
 then
   cp /etc/nginx/nginx.conf.default /etc/nginx/nginx.conf
 else