diff --git a/src/focus-visible.js b/src/focus-visible.js
index 0d7b3ed..d695378 100644
--- a/src/focus-visible.js
+++ b/src/focus-visible.js
@@ -269,6 +269,7 @@ function applyFocusVisiblePolyfill(scope) {
     scope.host.setAttribute('data-js-focus-visible', '');
   } else if (scope.nodeType === Node.DOCUMENT_NODE) {
     document.documentElement.classList.add('js-focus-visible');
+    document.documentElement.setAttribute('data-js-focus-visible', '');
   }
 }