diff --git a/modules/commerce_billy_pdf/commerce_billy_pdf.module b/modules/commerce_billy_pdf/commerce_billy_pdf.module
index bb9a13d..89cc5b0 100644
--- a/modules/commerce_billy_pdf/commerce_billy_pdf.module
+++ b/modules/commerce_billy_pdf/commerce_billy_pdf.module
@@ -159,6 +159,7 @@ function commerce_billy_pdf_html($orders) {
   foreach ($css_files as $file) {
     $vars['inline_css'] .= file_get_contents($file);
   }
+  drupal_alter('commerce_billy_pdf_html_prerender', $vars, $orders);
 
   return theme('commerce_billy_pdf_page', $vars);
 }
--