diff --git a/sphinx_wagtail_theme/layout.html b/sphinx_wagtail_theme/layout.html
index 978415c3..c8239357 100644
--- a/sphinx_wagtail_theme/layout.html
+++ b/sphinx_wagtail_theme/layout.html
@@ -103,7 +103,7 @@
     <div class="container-fluid">
         <div class="row">
             <aside class="col-12 col-lg-3">
-                <div id="collapseSidebar" class="collapse d-lg-block pt-5">
+                <div id="collapseSidebar" class="collapse sticky-top d-lg-block pt-5">
                     {%- if not theme_is_homepage and builder == 'html' %}
                         {%- include "searchbox.html" %}
                     {%- endif %}