diff --git a/dom.bs b/dom.bs
index b64fdffc..93a69f7f 100644
--- a/dom.bs
+++ b/dom.bs
@@ -6768,7 +6768,7 @@ invoked, must run these steps:
  "<code>span</code>", then <a>throw</a> a "{{NotSupportedError!!exception}}" {{DOMException}}.
 
  <li><p>If <a>context object</a> is a <a for=Element>shadow host</a>, then <a>throw</a> an
- "{{InvalidStateError!!exception}}" {{DOMException}}.
+ "{{NotSupportedError!!exception}}" {{DOMException}}.
 
  <li><p>Let <var>shadow</var> be a new <a for=/>shadow root</a> whose <a for=Node>node document</a>
  is <a>context object</a>'s <a for=Node>node document</a>, <a for=DocumentFragment>host</a> is