diff --git a/src/theme/book.js b/src/theme/book.js
index ca73ee14..263e8ad0 100644
--- a/src/theme/book.js
+++ b/src/theme/book.js
@@ -435,6 +435,7 @@ function playpen_text(playpen) {
 (function sidebar() {
     var html = document.querySelector("html");
     var sidebar = document.getElementById("sidebar");
+    var sidebarScrollBox = document.getElementById("sidebar-scrollbox");
     var sidebarLinks = document.querySelectorAll('#sidebar a');
     var sidebarToggleButton = document.getElementById("sidebar-toggle");
     var sidebarResizeHandle = document.getElementById("sidebar-resize-handle");
@@ -522,7 +523,7 @@ function playpen_text(playpen) {
     // Scroll sidebar to current active section
     var activeSection = sidebar.querySelector(".active");
     if (activeSection) {
-        sidebar.scrollTop = activeSection.offsetTop;
+        sidebarScrollBox.scrollTop = activeSection.offsetTop;
     }
 })();
 
diff --git a/src/theme/index.hbs b/src/theme/index.hbs
index 3ef89e7d..6240c11a 100644
--- a/src/theme/index.hbs
+++ b/src/theme/index.hbs
@@ -84,7 +84,7 @@
         </script>
 
         <nav id="sidebar" class="sidebar" aria-label="Table of contents">
-            <div class="sidebar-scrollbox">
+            <div id="sidebar-scrollbox" class="sidebar-scrollbox">
                 {{#toc}}{{/toc}}
             </div>
             <div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>