diff --git a/accessible/base/NotificationController.cpp b/accessible/base/NotificationController.cpp
index a583be8fdb9..497244733af 100644
--- a/accessible/base/NotificationController.cpp
+++ b/accessible/base/NotificationController.cpp
@@ -341,6 +341,7 @@ void NotificationController::DropMutationEvent(AccTreeMutationEvent* aEvent) {
     MOZ_ASSERT(hideEvent);
 
     if (hideEvent->NeedsShutdown()) {
+      mDocument->UncacheChildrenInSubtree(aEvent->GetAccessible());
       mDocument->ShutdownChildrenInSubtree(aEvent->GetAccessible());
     }
   } else {
diff --git a/accessible/generic/DocAccessible.cpp b/accessible/generic/DocAccessible.cpp
index e6fae058244..abf274597c9 100644
--- a/accessible/generic/DocAccessible.cpp
+++ b/accessible/generic/DocAccessible.cpp
@@ -1358,6 +1358,9 @@ void DocAccessible::UnbindFromDocument(LocalAccessible* aAccessible) {
   NS_ASSERTION(mAccessibleCache.GetWeak(aAccessible->UniqueID()),
                "Unbinding the unbound accessible!");
 
+  MOZ_ASSERT(!mARIAOwnsHash.Contains(aAccessible),
+             "Container still lingering in mARIAOwnsHash");
+
   // Fire focus event on accessible having DOM focus if last focus was removed
   // from the tree.
   if (FocusMgr()->WasLastFocused(aAccessible)) {