diff --git a/src/Mod/Start/Gui/AppStartGui.cpp b/src/Mod/Start/Gui/AppStartGui.cpp
index eded79a9cd..489a9160c7 100644
--- a/src/Mod/Start/Gui/AppStartGui.cpp
+++ b/src/Mod/Start/Gui/AppStartGui.cpp
@@ -70,7 +70,7 @@ PyMOD_INIT_FUNC(StartGui)
 {
     if (!Gui::Application::Instance) {
         PyErr_SetString(PyExc_ImportError, "Cannot load Gui module in console application.");
-        PyMOD_Return(0);
+        PyMOD_Return(nullptr);
     }
 
     // load dependent module
@@ -79,7 +79,7 @@ PyMOD_INIT_FUNC(StartGui)
     }
     catch(const Base::Exception& e) {
         PyErr_SetString(PyExc_ImportError, e.what());
-        PyMOD_Return(0);
+        PyMOD_Return(nullptr);
     }
     catch (Py::Exception& e) {
         Py::Object o = Py::type(e);
diff --git a/src/Mod/Start/Gui/DlgStartPreferencesImp.h b/src/Mod/Start/Gui/DlgStartPreferencesImp.h
index 171839a954..67b93dd233 100644
--- a/src/Mod/Start/Gui/DlgStartPreferencesImp.h
+++ b/src/Mod/Start/Gui/DlgStartPreferencesImp.h
@@ -34,7 +34,7 @@ namespace StartGui {
         Q_OBJECT
 
     public:
-        DlgStartPreferencesImp( QWidget* parent = 0 );
+        DlgStartPreferencesImp( QWidget* parent = nullptr );
         ~DlgStartPreferencesImp();
 
     protected: