diff --git a/layouts/partials/docs/inject/toc-before.html b/layouts/partials/docs/inject/toc-before.html
index 9ca3c64..05863a3 100644
--- a/layouts/partials/docs/inject/toc-before.html
+++ b/layouts/partials/docs/inject/toc-before.html
@@ -23,7 +23,7 @@
     <div class="tag-container">
       {{ range $.Params.tags }}
         <div class="post-tag">
-          <a href="/tags/{{ . }}">{{ . }}</a> <!-- The . represents an element in $array -->
+          <a href="/tags/{{ . | strings.ToLower }}">{{ . }}</a> <!-- The . represents an element in $array -->
         </div>
       {{ end }}
     </div>