diff --git a/src/gui/kernel/qinputpanel.h b/src/gui/kernel/qinputpanel.h
index 2348fbd62f..c88edbce36 100644
--- a/src/gui/kernel/qinputpanel.h
+++ b/src/gui/kernel/qinputpanel.h
@@ -53,6 +53,7 @@ QT_MODULE(Gui)
 class QInputPanelPrivate;
 class QWindow;
 class QRectF;
+class QTransform;
 
 class Q_GUI_EXPORT QInputPanel : public QObject
 {