diff --git a/src/Abstract/Entity/Browser/Container/Page/Content/Markup.php b/src/Abstract/Entity/Browser/Container/Page/Content/Markup.php
index ef74111f..b27789a3 100644
--- a/src/Abstract/Entity/Browser/Container/Page/Content/Markup.php
+++ b/src/Abstract/Entity/Browser/Container/Page/Content/Markup.php
@@ -16,6 +16,9 @@ abstract class Markup
     // Dependencies
     public Content $content;
 
+    // Extras
+    protected ?string $_source = null;
+
     // Defaults
     public const WRAP = 140;