diff --git a/examples/dragzoom.html b/examples/dragzoom.html
index 0cd64bb6c1..18becc24fe 100644
--- a/examples/dragzoom.html
+++ b/examples/dragzoom.html
@@ -32,8 +32,9 @@
 
         <div class="span12">
           <h4 id="title">DragZoom example</h4>
-          <p id="shortdesc">Example of dragzoom interaction</p>
+          <p id="shortdesc">Example of dragzoom interaction.</p>
           <div id="docs">
+            <p>Press SHIFT and drag the map to trigger the interaction.</p>
             <p>See the <a href="dragzoom.js" target="_blank">dragzoom.js source</a> to see how this is done.</p>
             <p>For the moment, only works with the <strong>canvas</strong> renderer.</p>
           </div>