Fix listing
diff --git a/pages/customdatatypes.html b/pages/customdatatypes.html
index 1f3d984..6b60f00 100644
--- a/pages/customdatatypes.html
+++ b/pages/customdatatypes.html
@@ -21,13 +21,13 @@
 <hr/>
 <a>Listing 1</a> - Extension Point Registration
 <pre class="codebox">
-   <extension
-         point="org.eclipse.emf.edapt.factories">
-      <factory
+   &lt;extension
+         point="org.eclipse.emf.edapt.factories"&gt;
+      &lt;factory
             class="library.edapt.LibraryFactoryImpl"
-            nsURI="http://library/v3">
-      </factory>
-   </extension>
+            nsURI="http://library/v3"&gt;
+      &lt;/factory&gt;
+   &lt;/extension&gt;
 </pre>
 <hr/>
 </p><p>