diff --git a/src/Mod/Mesh/App/AppMeshPy.cpp b/src/Mod/Mesh/App/AppMeshPy.cpp
index 17786526be..c6675395d2 100644
--- a/src/Mod/Mesh/App/AppMeshPy.cpp
+++ b/src/Mod/Mesh/App/AppMeshPy.cpp
@@ -185,14 +185,14 @@ private:
     Py::Object importer(const Py::Tuple& args)
     {
         char* Name;
-        char* DocName=0;
+        char* DocName=nullptr;
         if (!PyArg_ParseTuple(args.ptr(), "et|s","utf-8",&Name,&DocName))
             throw Py::Exception();
 
         std::string EncodedName = std::string(Name);
         PyMem_Free(Name);
 
-        App::Document *pcDoc = 0;
+        App::Document *pcDoc = nullptr;
         if (DocName) {
             pcDoc = App::GetApplication().getDocument(DocName);
         }
@@ -223,7 +223,7 @@ private:
         int exportAmfCompressed( hGrp->GetBool("ExportAmfCompressed", true) );
 
         static char *kwList[] = {"objectList", "filename", "tolerance",
-                                 "exportAmfCompressed", NULL};
+                                 "exportAmfCompressed", nullptr};
 
         if (!PyArg_ParseTupleAndKeywords( args.ptr(), keywds.ptr(),
                                           "Oet|dp",
diff --git a/src/Mod/Mesh/Gui/DlgDecimating.cpp b/src/Mod/Mesh/Gui/DlgDecimating.cpp
index 3b05c8f9d6..2606242a29 100644
--- a/src/Mod/Mesh/Gui/DlgDecimating.cpp
+++ b/src/Mod/Mesh/Gui/DlgDecimating.cpp
@@ -119,7 +119,7 @@ TaskDecimating::TaskDecimating()
 {
     widget = new DlgDecimating();
     Gui::TaskView::TaskBox* taskbox = new Gui::TaskView::TaskBox(
-        QPixmap(), widget->windowTitle(), false, 0);
+        QPixmap(), widget->windowTitle(), false, nullptr);
     taskbox->groupLayout()->addWidget(widget);
     Content.push_back(taskbox);
 
diff --git a/src/Mod/Mesh/Gui/DlgDecimating.h b/src/Mod/Mesh/Gui/DlgDecimating.h
index 6af1fa7acd..d988296969 100644
--- a/src/Mod/Mesh/Gui/DlgDecimating.h
+++ b/src/Mod/Mesh/Gui/DlgDecimating.h
@@ -36,7 +36,7 @@ class DlgDecimating : public QWidget
     Q_OBJECT
 
 public:
-    DlgDecimating(QWidget* parent = 0, Qt::WindowFlags fl = Qt::WindowFlags());
+    DlgDecimating(QWidget* parent = nullptr, Qt::WindowFlags fl = Qt::WindowFlags());
     ~DlgDecimating();
     void setNumberOfTriangles(int);
     double tolerance() const;
diff --git a/src/Mod/Mesh/Gui/Workbench.cpp b/src/Mod/Mesh/Gui/Workbench.cpp
index 822d6cdbfc..9f17387a73 100644
--- a/src/Mod/Mesh/Gui/Workbench.cpp
+++ b/src/Mod/Mesh/Gui/Workbench.cpp
@@ -63,7 +63,7 @@ Workbench::~Workbench()
 class MeshInfoWatcher : public Gui::TaskView::TaskWatcher, public Gui::SelectionObserver
 {
 public:
-    MeshInfoWatcher() : TaskWatcher(0)
+    MeshInfoWatcher() : TaskWatcher(nullptr)
     {
         labelPoints = new QLabel();
         labelPoints->setText(QString::fromLatin1("Number of points:"));
@@ -98,7 +98,7 @@ public:
         grid->addWidget(numMax, 3, 1);
 
         Gui::TaskView::TaskBox* taskbox = new Gui::TaskView::TaskBox(
-            QPixmap(), QString::fromLatin1("Mesh info"), false, 0);
+            QPixmap(), QString::fromLatin1("Mesh info"), false, nullptr);
         taskbox->groupLayout()->addWidget(box);
         Content.push_back(taskbox);
     }