diff --git a/Libraries/LibWeb/CSS/Default.css b/Libraries/LibWeb/CSS/Default.css
index c5ea35edab..5e01137bbc 100644
--- a/Libraries/LibWeb/CSS/Default.css
+++ b/Libraries/LibWeb/CSS/Default.css
@@ -48,6 +48,7 @@ blockquote,
 body, dd, div,
 dl, dt, fieldset, form,
 frame, frameset,
+hgroup,
 h1, h2, h3, h4,
 h5, h6, noframes,
 ol, p, ul, center,