Port to Qt 6
diff --git a/ide/CellModel.h b/ide/CellModel.h
index a946441..46f3628 100644
--- a/ide/CellModel.h
+++ b/ide/CellModel.h
@@ -3,9 +3,10 @@
 #include <QAbstractListModel>
 #include <qqml.h>
 
-#include "Notebook.h"
 #include "Cell.h"
 
+class Notebook;
+
 class CellModel : public QAbstractListModel
 {
     Q_OBJECT