diff --git a/utils/README.md b/utils/README.md
index ba13171..d27d5c9 100644
--- a/utils/README.md
+++ b/utils/README.md
@@ -1,4 +1,10 @@
 # Utils
+This folder has some scripts which are useful to do several small tasks.
+
+Before running any of them, you should first run `composer install` to install
+the dependencies (install [Composer][1] if it's not already installed in your
+computer).
+
 ## Send emails
 To send emails, run `php sendEmails.php < users.csv`, where `users.csv` has a
 form similar to the `sample.csv` file.
@@ -6,3 +12,5 @@
 Before you do that, you should copy `config.default.php` to `config.php` and
 set up the Mailgun API keys. You might also have to change the template ID in
 the `sendEmails.php` file.
+
+[1]: https://getcomposer.org/