diff --git a/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js b/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
index 0df11e86dea..dbf52cbef9f 100644
--- a/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
+++ b/addons/web_editor/static/src/js/editor/odoo-editor/src/utils/utils.js
@@ -1242,13 +1242,13 @@ export function isBlock(node) {
         return false;
     }
     // The node might not be in the DOM, in which case it has no CSS values.
-    if (window.document !== node.ownerDocument) {
+    if (!node.isConnected) {
         return blockTagNames.includes(tagName);
     }
     // We won't call `getComputedStyle` more than once per node.
     let style = computedStyles.get(node);
     if (!style) {
-        style = window.getComputedStyle(node);
+        style = node.ownerDocument.defaultView.getComputedStyle(node);
         computedStyles.set(node, style);
     }
     if (style.display) {