diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
index 6cbaa010782..46b39f01cc2 100644
--- a/Libraries/LibWeb/DOM/Document.cpp
+++ b/Libraries/LibWeb/DOM/Document.cpp
@@ -506,6 +506,7 @@ void Document::visit_edges(Cell::Visitor& visitor)
     visitor.visit(m_scripts_to_execute_as_soon_as_possible);
     visitor.visit(m_node_iterators);
     visitor.visit(m_document_observers);
+    visitor.visit(m_document_observers_being_notified);
     visitor.visit(m_pending_scroll_event_targets);
     visitor.visit(m_pending_scrollend_event_targets);
     visitor.visit(m_resize_observers);
@@ -2440,10 +2441,10 @@ void Document::update_readiness(HTML::DocumentReadyState readiness_value)
         }
     }
 
-    for (auto document_observer : m_document_observers) {
-        if (document_observer->document_readiness_observer())
-            document_observer->document_readiness_observer()->function()(m_readiness);
-    }
+    notify_each_document_observer([&](auto const& document_observer) {
+        return document_observer.document_readiness_observer();
+    },
+        m_readiness);
 }
 
 // https://html.spec.whatwg.org/multipage/dom.html#dom-document-lastmodified
@@ -2507,11 +2508,9 @@ void Document::completely_finish_loading()
         return;
 
     ScopeGuard notify_observers = [this] {
-        auto observers_to_notify = m_document_observers.values();
-        for (auto& document_observer : observers_to_notify) {
-            if (document_observer->document_completely_loaded())
-                document_observer->document_completely_loaded()->function()();
-        }
+        notify_each_document_observer([&](auto const& document_observer) {
+            return document_observer.document_completely_loaded();
+        });
     };
 
     // 1. Assert: document's browsing context is non-null.
@@ -2777,10 +2776,10 @@ void Document::update_the_visibility_state(HTML::VisibilityState visibility_stat
     m_visibility_state = visibility_state;
 
     // 3. Run any page visibility change steps which may be defined in other specifications, with visibility state and document.
-    for (auto document_observer : m_document_observers) {
-        if (document_observer->document_visibility_state_observer())
-            document_observer->document_visibility_state_observer()->function()(m_visibility_state);
-    }
+    notify_each_document_observer([&](auto const& document_observer) {
+        return document_observer.document_visibility_state_observer();
+    },
+        m_visibility_state);
 
     // 4. Fire an event named visibilitychange at document, with its bubbles attribute initialized to true.
     auto event = DOM::Event::create(realm(), HTML::EventNames::visibilitychange);
@@ -3090,10 +3089,10 @@ void Document::set_page_showing(bool page_showing)
 
     m_page_showing = page_showing;
 
-    for (auto document_observer : m_document_observers) {
-        if (document_observer->document_page_showing_observer())
-            document_observer->document_page_showing_observer()->function()(m_page_showing);
-    }
+    notify_each_document_observer([&](auto const& document_observer) {
+        return document_observer.document_page_showing_observer();
+    },
+        m_page_showing);
 }
 
 void Document::invalidate_stacking_context_tree()
@@ -3773,11 +3772,9 @@ void Document::did_stop_being_active_document_in_navigable()
 {
     tear_down_layout_tree();
 
-    auto observers_to_notify = m_document_observers.values();
-    for (auto& document_observer : observers_to_notify) {
-        if (document_observer->document_became_inactive())
-            document_observer->document_became_inactive()->function()();
-    }
+    notify_each_document_observer([&](auto const& document_observer) {
+        return document_observer.document_became_inactive();
+    });
 
     if (m_animation_driver_timer)
         m_animation_driver_timer->stop();
diff --git a/Libraries/LibWeb/DOM/Document.h b/Libraries/LibWeb/DOM/Document.h
index c5d6ad140fc..261e2b620f7 100644
--- a/Libraries/LibWeb/DOM/Document.h
+++ b/Libraries/LibWeb/DOM/Document.h
@@ -787,6 +787,21 @@ private:
 
     void dispatch_events_for_animation_if_necessary(GC::Ref<Animations::Animation>);
 
+    template<typename GetNotifier, typename... Args>
+    void notify_each_document_observer(GetNotifier&& get_notifier, Args&&... args)
+    {
+        ScopeGuard guard { [&]() { m_document_observers_being_notified.clear_with_capacity(); } };
+        m_document_observers_being_notified.ensure_capacity(m_document_observers.size());
+
+        for (auto observer : m_document_observers)
+            m_document_observers_being_notified.unchecked_append(observer);
+
+        for (auto document_observer : m_document_observers_being_notified) {
+            if (auto notifier = get_notifier(*document_observer))
+                notifier->function()(forward<Args>(args)...);
+        }
+    }
+
     GC::Ref<Page> m_page;
     OwnPtr<CSS::StyleComputer> m_style_computer;
     GC::Ptr<CSS::StyleSheetList> m_style_sheets;
@@ -897,6 +912,7 @@ private:
     HashTable<GC::Ptr<NodeIterator>> m_node_iterators;
 
     HashTable<GC::Ref<DocumentObserver>> m_document_observers;
+    Vector<GC::Ref<DocumentObserver>> m_document_observers_being_notified;
 
     // https://html.spec.whatwg.org/multipage/dom.html#is-initial-about:blank
     bool m_is_initial_about_blank { false };