diff --git a/src/window_func.h b/src/window_func.h
--- a/src/window_func.h
+++ b/src/window_func.h
@@ -39,4 +39,11 @@ void HideVitalWindows();
 void ShowVitalWindows();
 Window **FindWindowZPosition(const Window *w);
 
+void InvalidateWindow(WindowClass cls, WindowNumber number);
+void InvalidateWindowWidget(WindowClass cls, WindowNumber number, byte widget_index);
+void InvalidateWindowClasses(WindowClass cls);
+void InvalidateWindowClassesData(WindowClass cls);
+void DeleteWindowById(WindowClass cls, WindowNumber number);
+void DeleteWindowByClass(WindowClass cls);
+
 #endif /* WINDOW_FUNC_H */