diff --git a/docker_nginx_lets_encrypt.md b/docker_nginx_lets_encrypt.md
index 72d1138..8724340 100755
--- a/docker_nginx_lets_encrypt.md
+++ b/docker_nginx_lets_encrypt.md
@@ -88,7 +88,7 @@ server {
 Run the following command, replacing `REPLACEME` with your domain name:
 
 ```
-sed -i 's/DOMAIN.NAME/REPLACEME/g data/nginx/app.conf'
+sed -i 's/DOMAIN.NAME/REPLACEME/g' data/nginx/app.conf
 ```
 
 ## Get your first certificates