diff --git a/htdocs/core/class/html.formmail.class.php b/htdocs/core/class/html.formmail.class.php
index cadcee37b8c..ad6a6c12508 100644
--- a/htdocs/core/class/html.formmail.class.php
+++ b/htdocs/core/class/html.formmail.class.php
@@ -1697,4 +1697,9 @@ class ModelMail
 	public $content_lines;
 	public $lang;
 	public $joinfiles;
+
+	/**
+	 * @var string Module the template is dedicated for
+	 */
+	public $module;
 }