diff --git a/doc/api_assets/api.js b/doc/api_assets/api.js
index 546722cd908ce7..7bd7f646631eb0 100644
--- a/doc/api_assets/api.js
+++ b/doc/api_assets/api.js
@@ -119,7 +119,7 @@ function setupStickyHeaders() {
 }
 
 // Check if we have JavaScript support
-document.querySelector(':root').classList.add('has-js');
+document.documentElement.classList.add('has-js');
 
 // Restore user mode preferences
 setupTheme();