diff --git a/_layouts/default.html b/_layouts/default.html
index 2fbd948..618df63 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -36,7 +36,7 @@
     <button id="back-to-top"
        class="btn btn-primary btn-lg"
        title="Click to return to the start of the page" data-toggle="tooltip" data-placement="left">
-        <span class="fas fa-chevron-square-up"></span>
+        <span class="far fa-chevron-square-up"></span>
     </button>
 </div>
 {% include footer.html %}