diff --git a/doc/xschem_man/graphs.html b/doc/xschem_man/graphs.html
index df60995d..2fc8660f 100644
--- a/doc/xschem_man/graphs.html
+++ b/doc/xschem_man/graphs.html
@@ -113,6 +113,8 @@ p{padding: 15px  30px 10px;}
        configuration dialog box, where you can change many graph parameters.</li>
   <li> Pressing the <kbd>right</kbd> mouse button in the graph area and dragging some distance in the X direction 
        will zoom in the waveforms to that X range.</li>
+  <li> Pressing the <kbd>right</kbd> mouse button to the left of the Y axis and dragging some distance in the Y direction 
+       will zoom in the waveforms to that Y range.</li>
  </ul>
  <p>
   <img src="graphs07.png"><br>