diff --git a/site/_docs/configuration.md b/site/_docs/configuration.md
index e119196e..406ed416 100644
--- a/site/_docs/configuration.md
+++ b/site/_docs/configuration.md
@@ -87,6 +87,20 @@ class="flag">flags</code> (specified on the command-line) that control them.
         <p><code class="option">include: [DIR, FILE, ...]</code></p>
       </td>
     </tr>
+    <tr class="setting">
+      <td>
+        <p class="name"><strong>Keep files</strong></p>
+        <p class="description">
+          When clobbering the site destination, keep the selected files.
+          Useful for files that are not generated by jekyll; e.g. files or
+          assets that are generated by your build tool.
+          The paths are relative to the <code>destination</code>.
+        </p>
+      </td>
+      <td class="align-center">
+        <p><code class="option">keep_files: [DIR, FILE, ...]</code></p>
+      </td>
+    </tr>
     <tr class="setting">
       <td>
         <p class="name"><strong>Time Zone</strong></p>