diff --git a/index.html b/index.html
index 4cb8a94..c83d22a 100644
--- a/index.html
+++ b/index.html
@@ -153,7 +153,7 @@ clipboard.on('error', function(e) {
 
         <p>Each application has different design needs, that's why clipboard.js does not include any CSS or built-in tooltip solution.</p>
 
-        <p>The tooltips you see on this demo site were built using <a href="http://primercss.io/tooltips/">GitHub's Primer</a>. You may want to check that out if you're looking for a similar look and feel.</p>
+        <p>The tooltips you see on this demo site were built using <a href="https://github.com/primer/primer-css/tree/master/modules/primer-tooltips">GitHub's Primer</a>. You may want to check that out if you're looking for a similar look and feel.</p>
 
         <h1 id="advanced-usage">Advanced Usage</h1>