diff --git a/Plugins/org.blueberry.ui.qt/src/internal/berryQtControlWidget.h b/Plugins/org.blueberry.ui.qt/src/internal/berryQtControlWidget.h
index 1540f8b611..70bfe82b2d 100755
--- a/Plugins/org.blueberry.ui.qt/src/internal/berryQtControlWidget.h
+++ b/Plugins/org.blueberry.ui.qt/src/internal/berryQtControlWidget.h
@@ -1,58 +1,58 @@
 /*===================================================================
 
 BlueBerry Platform
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 
 #ifndef BERRYQTCONTROLWIDGET_H_
 #define BERRYQTCONTROLWIDGET_H_
 
 #include <QFrame>
 
 #include "berryQtWidgetController.h"
 
 #include <org_blueberry_ui_qt_Export.h>
 
 namespace berry {
 
 class BERRY_UI_QT QtControlWidget : public QFrame
 {
 
 public:
 
-  QtControlWidget(QWidget* parent, Shell* shell, Qt::WindowFlags f = nullptr);
+  QtControlWidget(QWidget* parent, Shell* shell, Qt::WindowFlags f = 0);
 
   ~QtControlWidget();
 
   void FireActivateEvent();
 
 protected:
 
   // used for shell listeners
   void changeEvent(QEvent* event) override;
   void closeEvent(QCloseEvent* closeEvent) override;
 
   // used for control listeners
   void moveEvent(QMoveEvent* event) override;
   void resizeEvent(QResizeEvent* event) override;
 
 
 private:
 
   QtWidgetController::Pointer controller;
 };
 
 }
 
 #endif /* BERRYQTCONTROLWIDGET_H_ */
diff --git a/Plugins/org.blueberry.ui.qt/src/internal/berryQtMainWindowControl.h b/Plugins/org.blueberry.ui.qt/src/internal/berryQtMainWindowControl.h
index c5a3ae2c02..ae6220206f 100755
--- a/Plugins/org.blueberry.ui.qt/src/internal/berryQtMainWindowControl.h
+++ b/Plugins/org.blueberry.ui.qt/src/internal/berryQtMainWindowControl.h
@@ -1,56 +1,56 @@
 /*===================================================================
 
 BlueBerry Platform
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 
 #ifndef BERRYQTMAINWINDOWCONTROL_H_
 #define BERRYQTMAINWINDOWCONTROL_H_
 
 #include <QMainWindow>
 
 #include <berryShell.h>
 #include <internal/berryQtWidgetController.h>
 
 namespace berry {
 
 class QtMainWindowControl : public QMainWindow
 {
 
   Q_OBJECT
 
 public:
 
-  QtMainWindowControl(Shell* shell, QWidget* parent = nullptr, Qt::WindowFlags flags = nullptr);
+  QtMainWindowControl(Shell* shell, QWidget* parent = nullptr, Qt::WindowFlags flags = 0);
 
 protected:
 
   // used for shell listeners
   void changeEvent(QEvent* event) override;
   void closeEvent(QCloseEvent* closeEvent) override;
 
   // used for control listeners
   void moveEvent(QMoveEvent* event) override;
   void resizeEvent(QResizeEvent* event) override;
   void inFocusEvent(QFocusEvent* event);
 
 private:
 
   QtWidgetController::Pointer controller;
 
 };
 
 }
 
 #endif /* BERRYQTMAINWINDOWCONTROL_H_ */
diff --git a/Plugins/org.blueberry.ui.qt/src/internal/berryQtShell.h b/Plugins/org.blueberry.ui.qt/src/internal/berryQtShell.h
index b626aec0db..d8b185460b 100755
--- a/Plugins/org.blueberry.ui.qt/src/internal/berryQtShell.h
+++ b/Plugins/org.blueberry.ui.qt/src/internal/berryQtShell.h
@@ -1,85 +1,85 @@
 /*===================================================================
 
 BlueBerry Platform
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 
 #ifndef BERRYQTMAINWINDOWSHELL_H_
 #define BERRYQTMAINWINDOWSHELL_H_
 
 #include <berryShell.h>
 
 #include <QWidget>
 
 namespace berry {
 
 class QtAbstractControlWidget;
 
 class QtShell : public Shell
 {
 
 public:
 
-  QtShell(QWidget* parent = nullptr, Qt::WindowFlags flags = nullptr);
+  QtShell(QWidget* parent = nullptr, Qt::WindowFlags flags = 0);
 
   ~QtShell();
 
   // berry::Shell
   void SetBounds(const QRect& bounds) override;
   QRect GetBounds() const override;
 
   void SetLocation(int x, int y) override;
 
   QPoint ComputeSize(int wHint, int hHint, bool changed) override;
 
   QString GetText() const override;
   void SetText(const QString& text) override;
 
   bool IsVisible() const override;
   void SetVisible(bool visible) override;
 
   void SetActive() override;
 
   QWidget* GetControl() const override;
 
   void SetImages(const QList<QIcon>& images) override;
 
   bool GetMaximized() const override;
   bool GetMinimized() const override;
   void SetMaximized(bool maximized) override;
   void SetMinimized(bool minimized) override;
 
   void AddShellListener(IShellListener* listener) override;
   void RemoveShellListener(IShellListener* listener) override;
 
   void Open(bool block = false) override;
 
   void Close() override;
 
   QList<Shell::Pointer> GetShells() override;
 
   Qt::WindowFlags GetStyle () const override;
 
   QWidget* GetWidget();
 
 private:
 
   QWidget* widget;
   bool updatesDisabled;
 
 };
 
 }
 
 #endif /* BERRYQTMAINWINDOWSHELL_H_ */
diff --git a/Plugins/org.blueberry.ui.qt/src/internal/berryQtShowViewDialog.h b/Plugins/org.blueberry.ui.qt/src/internal/berryQtShowViewDialog.h
index 72d573ea4d..c2a7ef1b83 100644
--- a/Plugins/org.blueberry.ui.qt/src/internal/berryQtShowViewDialog.h
+++ b/Plugins/org.blueberry.ui.qt/src/internal/berryQtShowViewDialog.h
@@ -1,73 +1,73 @@
 /*===================================================================
 
 BlueBerry Platform
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 #ifndef BERRYQTSHOWVIEWDIALOG_H_
 #define BERRYQTSHOWVIEWDIALOG_H_
 
 #include <berrySmartPointer.h>
 
 #include <QDialog>
 
 #include "ui_berryQtShowViewDialog.h"
 
 namespace berry {
 
 struct IViewRegistry;
 struct IWorkbenchWindow;
 
 class ViewFilterProxyModel;
 
 class QtShowViewDialog : public QDialog
 {
   Q_OBJECT
 
 public:
 
   QtShowViewDialog(const IWorkbenchWindow* window, IViewRegistry* registry,
-                   QWidget* parent = nullptr, Qt::WindowFlags f = nullptr);
+                   QWidget* parent = nullptr, Qt::WindowFlags f = 0);
 
   QList<QString> GetSelection() const;
 
 private:
 
   Q_SLOT void setDescription(const QModelIndex& index);
   Q_SLOT void enableKeywordFilter(bool enable);
 
   Q_SLOT void setFilter(const QString& filter);
 
   Q_SLOT void categoryCollapsed(const QModelIndex& index);
   Q_SLOT void categoryExpanded(const QModelIndex& index);
 
   Q_SLOT void selectionChanged(const QItemSelection& selected, const QItemSelection& deselected);
 
   void RestoreExpandedState();
   void UpdateButtons();
 
   void RestoreState();
   void SaveState();
 
   void done(int r) override;
 
   const IWorkbenchWindow* m_Window;
   IViewRegistry* m_ViewReg;
   Ui::QtShowViewDialog_ m_UserInterface;
   ViewFilterProxyModel* m_FilterModel;
   QList<QPersistentModelIndex> m_ExpandedCategories;
 };
 
 }
 
 #endif /*BERRYQTSHOWVIEWDIALOG_H_*/
diff --git a/Plugins/org.mitk.gui.qt.application/src/QmitkPreferencesDialog.h b/Plugins/org.mitk.gui.qt.application/src/QmitkPreferencesDialog.h
index cc593a38f2..be6f68a2ba 100644
--- a/Plugins/org.mitk.gui.qt.application/src/QmitkPreferencesDialog.h
+++ b/Plugins/org.mitk.gui.qt.application/src/QmitkPreferencesDialog.h
@@ -1,68 +1,68 @@
 /*===================================================================
 
 The Medical Imaging Interaction Toolkit (MITK)
 
 Copyright (c) German Cancer Research Center,
 Division of Medical and Biological Informatics.
 All rights reserved.
 
 This software is distributed WITHOUT ANY WARRANTY; without
 even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.
 
 See LICENSE.txt or http://www.mitk.org for details.
 
 ===================================================================*/
 
 
 #ifndef BERRYQMITKPREFERENCESDIALOG_H_
 #define BERRYQMITKPREFERENCESDIALOG_H_
 
 #include <org_mitk_gui_qt_application_Export.h>
 
 #include <QDialog>
 #include <QScopedPointer>
 
 
 class QmitkPreferencesDialogPrivate;
 
 /**
  * \ingroup org_mitk_gui_qt_application
  */
 class MITK_QT_APP QmitkPreferencesDialog : public QDialog
 {
     Q_OBJECT
 
 public:
 
-    QmitkPreferencesDialog(QWidget * parent = nullptr, Qt::WindowFlags f = nullptr);
+    QmitkPreferencesDialog(QWidget * parent = nullptr, Qt::WindowFlags f = 0);
     ~QmitkPreferencesDialog();
 
     void SetSelectedPage(const QString& id);
 
 protected slots:
 
   void OnImportButtonClicked();
   void OnExportButtonClicked();
   void OnDialogAccepted();
   void OnDialogRejected();
 
   void OnKeywordTextChanged(const QString & s);
   void OnKeywordEditingFinished();
   void OnPreferencesTreeItemSelectionChanged();
 
 protected:
 
   //bool eventFilter(QObject *obj, QEvent *event);
   void UpdateTree();
 
   ///
   /// Saves all preferencepages.
   ///
   void SavePreferences();
 
   QScopedPointer<QmitkPreferencesDialogPrivate> d;
 
 };
 
 #endif /* BERRYQMITKPREFERENCESDIALOG_H_ */