diff --git a/fhem/FHEM/10_OWServer.pm b/fhem/FHEM/10_OWServer.pm
index 5107d148c..2b1eb1e52 100644
--- a/fhem/FHEM/10_OWServer.pm
+++ b/fhem/FHEM/10_OWServer.pm
@@ -615,6 +615,7 @@ OWServer_Set($@)
     <li><a href="#readingFnAttributes">readingFnAttributes</a></li>
   </ul>
   <br><br>
+  Note: unset <code>nonblocking</code> if you experience lockups of FHEM.
 
 </ul>