diff --git a/layouts/partials/table_of_contents.html b/layouts/partials/table_of_contents.html
index 70a2f45..e6fa931 100644
--- a/layouts/partials/table_of_contents.html
+++ b/layouts/partials/table_of_contents.html
@@ -1,6 +1,6 @@
-{{ if and (gt .WordCount 400) .Params.toc }}
-<aside>
-  <details open>
+{{ if and (gt .WordCount 400) (isset .Params "toc") .Params.toc }}
+<aside id="table-of-contents">
+  <details {{ if eq .Params.toc "open" }}open{{ end }}>
     <summary>Table of Contents</summary>
     {{ .TableOfContents }}
   </details>