diff --git a/Documentation/NuttxPortingGuide.html b/Documentation/NuttxPortingGuide.html
index a381c6a673..4c730524ab 100644
--- a/Documentation/NuttxPortingGuide.html
+++ b/Documentation/NuttxPortingGuide.html
@@ -1639,6 +1639,13 @@ The system can be re-made subsequently by just typing <code>make</code>.
     are only using semaphores as mutexes (only one holder) OR if no more
     than two threads participate using a counting semaphore.
   </li>
+  <li>
+    <code>CONFIG_SEM_NNESTPRIO. </code>: If priority inheritance is enabled,
+    then this setting is the maximum number of higher priority threads (minus
+    1) than can be waiting for another thread to release a count on a semaphore.
+    This value may be set to zero if no more than one thread is expected to
+    wait for a semaphore.
+  </li>
 </ul>
 
 <p>