diff --git a/lib/common/html_blocks.js b/lib/common/html_blocks.js
index 515fb00..26cb58b 100644
--- a/lib/common/html_blocks.js
+++ b/lib/common/html_blocks.js
@@ -31,6 +31,11 @@ module.exports = [
   'frame',
   'frameset',
   'h1',
+  'h2',
+  'h3',
+  'h4',
+  'h5',
+  'h6',
   'head',
   'header',
   'hr',