diff --git a/lib/common/html_blocks.js b/lib/common/html_blocks.js
index 1accba4f..f2e007c1 100644
--- a/lib/common/html_blocks.js
+++ b/lib/common/html_blocks.js
@@ -14,6 +14,7 @@ var html_blocks = {};
   'col',
   'colgroup',
   'dd',
+  'details',
   'div',
   'dl',
   'dt',