diff --git a/docker_nginx_lets_encrypt.md b/docker_nginx_lets_encrypt.md
index 4e9efbb..8cc6de2 100755
--- a/docker_nginx_lets_encrypt.md
+++ b/docker_nginx_lets_encrypt.md
@@ -22,7 +22,7 @@ Notice how `certbot`'s `entrypoint` field is commented out?
 Yeah, that's one of the things that tripped me up.
 When the autorenew entrypoint is specified, you can't perform one of the future steps.
 
-```
+```yaml
 version: '3'
 
 services: