diff --git a/_includes/package-nav.html b/_includes/package-nav.html
index 314ca6a..27936cd 100644
--- a/_includes/package-nav.html
+++ b/_includes/package-nav.html
@@ -1,3 +1,4 @@
+<li><a href="tidy.html">Tidy data</a></li>
 <!--
 <li class="dropdown-header">R for Data Science</li>
 <li><a href="intro.html">Introduction to data science</a></li>