diff --git a/src/Gui/Tree.cpp b/src/Gui/Tree.cpp
index c03d10cd68..dd3c55cd90 100644
--- a/src/Gui/Tree.cpp
+++ b/src/Gui/Tree.cpp
@@ -32,7 +32,7 @@
 # include <QCursor>
 # include <QHeaderView>
 # include <QMenu>
-# include <QMessageBox.h>
+# include <QMessageBox>
 # include <QPixmap>
 # include <QTimer>
 # include <QToolTip>