diff --git a/doc/api_assets/api.js b/doc/api_assets/api.js
index 546722cd908ce7..3e7cf017f602ee 100644
--- a/doc/api_assets/api.js
+++ b/doc/api_assets/api.js
@@ -118,14 +118,16 @@ function setupStickyHeaders() {
   ).observe(header);
 }
 
-// Check if we have JavaScript support
-document.querySelector(':root').classList.add('has-js');
+document.addEventListener('DOMContentLoaded', function() {
+  // Check if we have JavaScript support
+  document.querySelector(':root').classList.add('has-js');
 
-// Restore user mode preferences
-setupTheme();
+  // Restore user mode preferences
+  setupTheme();
 
-// Handle pickers with click/taps rather than hovers
-setupPickers();
+  // Handle pickers with click/taps rather than hovers
+  setupPickers();
 
-// Track when the header is in sticky position
-setupStickyHeaders();
+  // Track when the header is in sticky position
+  setupStickyHeaders();
+}, { once: true });
diff --git a/doc/template.html b/doc/template.html
index a65e51d9d46bae..94e2937dcaf897 100644
--- a/doc/template.html
+++ b/doc/template.html
@@ -74,6 +74,6 @@ <h1>Node.js __VERSION__ documentation</h1>
       </div>
     </div>
   </div>
-  <script src="assets/api.js" type="text/javascript"></script>
+  <script defer src="assets/api.js" type="text/javascript"></script>
 </body>
 </html>