diff --git a/.themes/classic/source/_includes/head.html b/.themes/classic/source/_includes/head.html
index 6b5412ca646..48d1018fca5 100644
--- a/.themes/classic/source/_includes/head.html
+++ b/.themes/classic/source/_includes/head.html
@@ -15,6 +15,7 @@
+
{% capture canonical %}{{ site.url }}{% if site.permalink contains '.html' %}{{ page.url }}{% else %}{{ page.url | remove:'index.html' | strip_slash }}{% endif %}{% endcapture %}