diff --git a/pelican/themes/simple/templates/base.html b/pelican/themes/simple/templates/base.html
index a1017219..ad2723fd 100644
--- a/pelican/themes/simple/templates/base.html
+++ b/pelican/themes/simple/templates/base.html
@@ -21,7 +21,7 @@
           {% endfor %}
         {% else %}
           {% for cat, null in categories %}
-            <li{% if cat == category %} class="active"{% endif %}><a href="{{ SITEURL }}/category/{{ cat }}.html">{{ cat }}</a></li>
+            <li{% if cat == category %} class="active"{% endif %}><a href="{{ SITEURL }}/{{ cat.url }}">{{ cat }}</a></li>
           {% endfor %}
         {% endif %}
         </ul></nav><!-- /#menu -->