diff --git a/third_party/blink/renderer/core/dom/node.cc b/third_party/blink/renderer/core/dom/node.cc
index 4dece285b7ab3..fa64b76eaab95 100644
--- a/third_party/blink/renderer/core/dom/node.cc
+++ b/third_party/blink/renderer/core/dom/node.cc
@@ -57,6 +57,7 @@
 #include "third_party/blink/renderer/core/dom/events/event_dispatcher.h"
 #include "third_party/blink/renderer/core/dom/events/event_listener.h"
 #include "third_party/blink/renderer/core/dom/events/event_path.h"
+#include "third_party/blink/renderer/core/dom/events/scoped_event_queue.h"
 #include "third_party/blink/renderer/core/dom/flat_tree_node_data.h"
 #include "third_party/blink/renderer/core/dom/flat_tree_traversal.h"
 #include "third_party/blink/renderer/core/dom/focus_params.h"
@@ -771,12 +772,22 @@ void Node::moveBefore(Node* new_child,
   // impossible for nested `moveBefore()` calls to occur. Assert that no atomic
   // move is already in progress.
   DCHECK(!GetDocument().StatePreservingAtomicMoveInProgress());
-  GetDocument().SetStatePreservingAtomicMoveInProgress(true);
 
   ContainerNode* old_parent = new_child->parentNode();
 
-  insertBefore(new_child, ref_child, exception_state);
-  GetDocument().SetStatePreservingAtomicMoveInProgress(false);
+  // Any scoped event (e.g. `change` from SpinButtonElement::ReleaseCapture()
+  // reached via HTMLFieldSetElement::ChildrenChanged()) that is queued during
+  // the atomic move must not be dispatched while the
+  // StatePreservingAtomicMoveInProgress flag is set, otherwise author script
+  // can run inside the atomic move and remove iframes without disconnecting
+  // their content frames. Hold an outer EventQueueScope so deferred events
+  // only fire after the flag has been cleared.
+  {
+    EventQueueScope defer_scoped_events;
+    GetDocument().SetStatePreservingAtomicMoveInProgress(true);
+    insertBefore(new_child, ref_child, exception_state);
+    GetDocument().SetStatePreservingAtomicMoveInProgress(false);
+  }
 
   if (exception_state.HadException()) {
     return;