diff --git a/Libraries/LibGUI/Forward.h b/Libraries/LibGUI/Forward.h
index 97c6977c4f..4c1068f21a 100644
--- a/Libraries/LibGUI/Forward.h
+++ b/Libraries/LibGUI/Forward.h
@@ -34,9 +34,11 @@ class ActionGroup;
 class Application;
 class BoxLayout;
 class Button;
+class CheckBox;
 class Command;
 class FileSystemModel;
 class Frame;
+class GroupBox;
 class HorizontalBoxLayout;
 class ItemView;
 class JsonArrayModel;
@@ -55,6 +57,7 @@ class Painter;
 class ResizeCorner;
 class ScrollBar;
 class Slider;
+class SpinBox;
 class Splitter;
 class StackWidget;
 class StatusBar;