diff --git a/docker-compose.yml b/docker-compose.yml
index 5bcb5ad..433e1c6 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,15 +3,15 @@ services:
     image: alpine:latest
     volumes:
       - tls-certs:/etc/nginx/ssl
-    command: >
-      sh -c "
+    command: |
+      sh -c '
         apk add --no-cache openssl &&
-        openssl req -x509 -nodes -days 3650 -newkey rsa:2048
-          -keyout /etc/nginx/ssl/key.pem
-          -out /etc/nginx/ssl/cert.pem
-          -subj '/CN=localhost' &&
+        openssl req -x509 -nodes -days 3650 -newkey rsa:2048 \
+          -keyout /etc/nginx/ssl/key.pem \
+          -out /etc/nginx/ssl/cert.pem \
+          -subj "/CN=localhost" &&
         chmod 644 /etc/nginx/ssl/cert.pem /etc/nginx/ssl/key.pem
-      "
+      '
 
   nginx:
     image: nginx:latest