diff --git a/source b/source
index 2677dae1b8a..5c17e790d5a 100644
--- a/source
+++ b/source
@@ -13605,8 +13605,8 @@ Transport Protocol">HTTP&lt;/abbr> today.&lt;/p></code></pre> <!-- DO NOT REWRAP
      <li><p>Let <var>result</var> be the <span>auto directionality</span> of
      <var>element</var>.</p></li>
 
-     <li><p>If <var>result</var> is null, then return the <span>parent directionality</span> of
-     <var>element</var>.</p></li>
+     <li><p>If <var>result</var> is null, then return '<span
+     data-x="concept-ltr">ltr</span>'.</p></li>
 
      <li><p>Return <var>result</var>.</p></li>
     </ol>
@@ -13615,9 +13615,18 @@ Transport Protocol">HTTP&lt;/abbr> today.&lt;/p></code></pre> <!-- DO NOT REWRAP
    <dt><span data-x="attr-dir-undefined-state">undefined</span></dt>
    <dd>
     <dl class="switch">
-     <dt>If <var>element</var> is a <code>bdi</code> element and the <span>auto
-     directionality</span> of <var>element</var> is not null</dt>
-     <dd><p>Return the <span>auto directionality</span> of <var>element</var>.</p></dd>
+     <dt>If <var>element</var> is a <code>bdi</code> element</dt>
+     <dd>
+      <ol>
+       <li><p>Let <var>result</var> be the <span>auto directionality</span> of
+       <var>element</var>.</p></li>
+
+       <li><p>If <var>result</var> is null, then return '<span
+       data-x="concept-ltr">ltr</span>'.</p></li>
+
+       <li><p>Return <var>result</var>.</p></li>
+      </ol>
+     </dd>
 
      <dt>If <var>element</var> is an <code>input</code> element whose <code
      data-x="attr-input-type">type</code> attribute is in the <span