diff --git a/Libraries/LibCore/Object.h b/Libraries/LibCore/Object.h
index eaaded970a..972895ebb8 100644
--- a/Libraries/LibCore/Object.h
+++ b/Libraries/LibCore/Object.h
@@ -118,8 +118,6 @@ public:
     void deferred_invoke(Function<void(Object&)>);
 
     bool is_widget() const { return m_widget; }
-    virtual bool is_action() const { return false; }
-    virtual bool is_window() const { return false; }
 
     void save_to(AK::JsonObject&);
 
diff --git a/Libraries/LibGUI/Action.h b/Libraries/LibGUI/Action.h
index e0ab724b79..b7a9d0d6ed 100644
--- a/Libraries/LibGUI/Action.h
+++ b/Libraries/LibGUI/Action.h
@@ -144,8 +144,6 @@ public:
     void set_group(Badge<ActionGroup>, ActionGroup*);
 
 private:
-    virtual bool is_action() const override { return true; }
-
     Action(const StringView& text, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
     Action(const StringView& text, const Shortcut&, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
     Action(const StringView& text, const Shortcut&, RefPtr<Gfx::Bitmap>&& icon, Function<void(Action&)> = nullptr, Core::Object* = nullptr, bool checkable = false);
diff --git a/Libraries/LibGUI/Dialog.cpp b/Libraries/LibGUI/Dialog.cpp
index 66c5bd59e8..7de39c682d 100644
--- a/Libraries/LibGUI/Dialog.cpp
+++ b/Libraries/LibGUI/Dialog.cpp
@@ -45,7 +45,7 @@ int Dialog::exec()
 {
     ASSERT(!m_event_loop);
     m_event_loop = make<Core::EventLoop>();
-    if (parent() && parent()->is_window()) {
+    if (parent() && is<Window>(parent())) {
         auto& parent_window = *static_cast<Window*>(parent());
         if (parent_window.is_visible()) {
             center_within(parent_window);
diff --git a/Libraries/LibGUI/Window.cpp b/Libraries/LibGUI/Window.cpp
index 7fcd0ee14b..ed2f6ef87b 100644
--- a/Libraries/LibGUI/Window.cpp
+++ b/Libraries/LibGUI/Window.cpp
@@ -142,7 +142,7 @@ void Window::show()
 Window* Window::find_parent_window()
 {
     for (auto* ancestor = parent(); ancestor; ancestor = ancestor->parent()) {
-        if (ancestor->is_window())
+        if (is<Window>(ancestor))
             return static_cast<Window*>(ancestor);
     }
     return nullptr;
diff --git a/Libraries/LibGUI/Window.h b/Libraries/LibGUI/Window.h
index ac9665b859..ee0d969748 100644
--- a/Libraries/LibGUI/Window.h
+++ b/Libraries/LibGUI/Window.h
@@ -204,8 +204,6 @@ protected:
     virtual void wm_event(WMEvent&);
 
 private:
-    virtual bool is_window() const override final { return true; }
-
     void update_cursor();
     void focus_a_widget_if_possible(FocusSource);