diff --git a/docs/doxygen/htmlfooter.inc b/docs/doxygen/htmlfooter.inc
index bb0552fa30..3deabdee31 100644
--- a/docs/doxygen/htmlfooter.inc
+++ b/docs/doxygen/htmlfooter.inc
@@ -6,7 +6,7 @@
 <tr>
     <td align="left">
         <a href="http://www.wxwidgets.org" style="margin-left: 0px">
-            <img src="powered-by-wxwidgets.png">
+            <img src="powered-by-wxwidgets.png" alt="wxWidgets logo">
         </a>
     </td>
     <td valign="middle" align="center"><p class="footer">Page generated <tt>$datetime</tt> by <a href="http://www.doxygen.org">Doxygen</a> $doxygenversion</p></td>