diff --git a/billing.md b/billing.md
index d7dabcdbb4..7f457c9d4c 100644
--- a/billing.md
+++ b/billing.md
@@ -1882,7 +1882,7 @@ You may pass an array of prices to the `previewInvoice` method in order to previ
 
 Before generating invoice PDFs, you should use Composer to install the Dompdf library, which is the default invoice renderer for Cashier:
 
-```php
+```shell
 composer require dompdf/dompdf
 ```