diff --git a/doc/optional.html b/doc/optional.html
index 9c60bae..c794e2c 100644
--- a/doc/optional.html
+++ b/doc/optional.html
@@ -119,7 +119,7 @@ if ( p.second )
   languages as a <b>discriminated union</b> of <code>T</code> and <code>nil_t</code>.
   Discriminated unions are often called <i>variants</i>. A variant has a <i>current type</i>,
   which in our case is either <code>T</code> or <code>nil_t</code>.<br>
-  Using the <a href="../../variant/doc/index.html">Boost.Variant</a> library, this model can be implemented
+  Using the <a href="../../../doc/html/variant.html">Boost.Variant</a> library, this model can be implemented
   in terms of <code>boost::variant&lt;T,nil_t&gt;</code>.<br>
   There is precedence for a discriminated union as a model for an optional value: the
   <a href="http://www.haskell.org/"><u>Haskell</u></a> <b>Maybe</b> builtin type constructor,