diff --git a/_includes/head.html b/_includes/head.html
index deefddd..c95c794 100644
--- a/_includes/head.html
+++ b/_includes/head.html
@@ -5,10 +5,10 @@
     <div class="wrap">
         <h1 itemprop="name">SQL Style Guide</h1>
         <p class="author" itemprop="author" itemscope itemtype="http://schema.org/Person">by 
-            <a href="https://www.simonholywell.com/?utm_source=sqlstyle.guide&utm_medium=link&utm_campaign=header" itemprop="url"><span itemprop="name">Simon Holywell</span></a> &middot;
+            <a href="https://www.simonholywell.com/?utm_source={{ site.domain }}-sqlstyle.guide&utm_medium=link&utm_campaign=header" itemprop="url"><span itemprop="name">Simon Holywell</span></a> &middot;
             <a href="https://twitter.com/treffynnon">@Treffynnon</a>
         </p>
         <p class="twitter"><a href="https://twitter.com/share" class="twitter-share-button" data-url="{{ site.url }}" data-text="SQL style guide by @treffynnon: {{ site.description }}" data-size="large" data-dnt="true">Tweet</a>
         </p>
     </div>
-</header>
\ No newline at end of file
+</header>