diff --git a/doc/03-cli.md b/doc/03-cli.md
index 57e1d08c5..7864ea904 100644
--- a/doc/03-cli.md
+++ b/doc/03-cli.md
@@ -583,6 +583,8 @@ For example:
 COMPOSER=composer-other.json php composer.phar install
 ```
 
+The generated lock file will use the same name: `composer-other.lock` in this example.
+
 ### COMPOSER_ROOT_VERSION
 
 By setting this var you can specify the version of the root package, if it can