diff --git a/src/Gui/CommandDoc.cpp b/src/Gui/CommandDoc.cpp
index e9ee1d000a..dc5770d72f 100644
--- a/src/Gui/CommandDoc.cpp
+++ b/src/Gui/CommandDoc.cpp
@@ -1472,7 +1472,7 @@ void StdCmdTransform::activated(int iMsg)
 
 bool StdCmdTransform::isActive(void)
 {
-    return (Gui::Control().activeDialog()==nullptr);
+    return (Gui::Control().activeDialog() == nullptr);
 }
 
 //===========================================================================
diff --git a/src/Gui/CommandLink.cpp b/src/Gui/CommandLink.cpp
index 89d4be14c4..fc04f90864 100644
--- a/src/Gui/CommandLink.cpp
+++ b/src/Gui/CommandLink.cpp
@@ -734,7 +734,7 @@ static App::DocumentObject *getSelectedLink(bool finalLink, std::string *subname
 }
 
 bool StdCmdLinkSelectLinked::isActive() {
-    return getSelectedLink(false)!=nullptr;
+    return getSelectedLink(false) != nullptr;
 }
 
 void StdCmdLinkSelectLinked::activated(int)
@@ -779,7 +779,7 @@ StdCmdLinkSelectLinkedFinal::StdCmdLinkSelectLinkedFinal()
 }
 
 bool StdCmdLinkSelectLinkedFinal::isActive() {
-    return getSelectedLink(true)!=nullptr;
+    return getSelectedLink(true) != nullptr;
 }
 
 void StdCmdLinkSelectLinkedFinal::activated(int) {
diff --git a/src/Gui/CommandTest.cpp b/src/Gui/CommandTest.cpp
index 3e745de98f..80d4e1428a 100644
--- a/src/Gui/CommandTest.cpp
+++ b/src/Gui/CommandTest.cpp
@@ -162,7 +162,7 @@ void FCCmdTest2::activated(int iMsg)
 
 bool FCCmdTest2::isActive(void)
 {
-    return (getDocument()!=nullptr);
+    return (getDocument() != nullptr);
 }
 
 //===========================================================================
@@ -192,7 +192,7 @@ void FCCmdTest3::activated(int iMsg)
 
 bool FCCmdTest3::isActive(void)
 {
-    return (getDocument()!=nullptr);
+    return (getDocument() != nullptr);
 }
 
 //===========================================================================
@@ -223,7 +223,7 @@ void FCCmdTest4::activated(int iMsg)
 
 bool FCCmdTest4::isActive(void)
 {
-    return (getDocument()!=nullptr);
+    return (getDocument() != nullptr);
 }
 
 //===========================================================================
@@ -252,7 +252,7 @@ void FCCmdTest5::activated(int iMsg)
 
 bool FCCmdTest5::isActive(void)
 {
-  return (getDocument()!=nullptr);
+  return (getDocument() != nullptr);
 }
 
 
@@ -282,7 +282,7 @@ void FCCmdTest6::activated(int iMsg)
 
 bool FCCmdTest6::isActive(void)
 {
-    return (getDocument()!=nullptr);
+    return (getDocument() != nullptr);
 }
 
 //===========================================================================
@@ -332,7 +332,7 @@ void CmdTestCmdFuncs::activated(int iMsg)
 
 bool CmdTestCmdFuncs::isActive(void)
 {
-    return (getDocument()!=nullptr);
+    return (getDocument() != nullptr);
 }
 
 //===========================================================================
diff --git a/src/Gui/CommandView.cpp b/src/Gui/CommandView.cpp
index 551df9e074..a86e805432 100644
--- a/src/Gui/CommandView.cpp
+++ b/src/Gui/CommandView.cpp
@@ -1942,7 +1942,7 @@ void StdCmdViewCreate::activated(int iMsg)
 
 bool StdCmdViewCreate::isActive(void)
 {
-    return (getActiveGuiDocument()!=nullptr);
+    return (getActiveGuiDocument() != nullptr);
 }
 
 //===========================================================================
@@ -2995,7 +2995,7 @@ bool StdCmdTreeSelectAllInstances::isActive(void)
     if(!obj || !obj->getNameInDocument())
         return false;
     return dynamic_cast<ViewProviderDocumentObject*>(
-            Application::Instance->getViewProvider(obj))!=nullptr;
+            Application::Instance->getViewProvider(obj)) != nullptr;
 }
 
 void StdCmdTreeSelectAllInstances::activated(int iMsg)
@@ -3170,7 +3170,7 @@ bool StdCmdTextureMapping::isActive(void)
 {
     Gui::MDIView* view = getMainWindow()->activeWindow();
     return view && view->isDerivedFrom(Gui::View3DInventor::getClassTypeId())
-                && (Gui::Control().activeDialog()==nullptr);
+                && (Gui::Control().activeDialog() == nullptr);
 }
 
 DEF_STD_CMD(StdCmdDemoMode)
diff --git a/src/Gui/DAGView/DAGModel.cpp b/src/Gui/DAGView/DAGModel.cpp
index 7eb0821964..75509c1d18 100644
--- a/src/Gui/DAGView/DAGModel.cpp
+++ b/src/Gui/DAGView/DAGModel.cpp
@@ -1095,7 +1095,7 @@ void Model::contextMenuEvent(QGraphicsSceneContextMenuEvent* event)
 
 void Model::onRenameSlot()
 {
-  assert(proxy == nullptr);
+  assert(!proxy);
   std::vector<Gui::DAG::Vertex> selections = getAllSelected();
   assert(selections.size() == 1);
   
diff --git a/src/Gui/DlgExpressionInput.cpp b/src/Gui/DlgExpressionInput.cpp
index 942d3007ee..82d642a3dd 100644
--- a/src/Gui/DlgExpressionInput.cpp
+++ b/src/Gui/DlgExpressionInput.cpp
@@ -51,7 +51,7 @@ DlgExpressionInput::DlgExpressionInput(const App::ObjectIdentifier & _path,
   , impliedUnit(_impliedUnit)
   , minimumWidth(10)
 {
-    assert(path.getDocumentObject() != nullptr);
+    assert(path.getDocumentObject());
 
     // Setup UI
     ui->setupUi(this);
diff --git a/src/Gui/ExpressionBinding.cpp b/src/Gui/ExpressionBinding.cpp
index 4f4cbb3d74..3878a7041a 100644
--- a/src/Gui/ExpressionBinding.cpp
+++ b/src/Gui/ExpressionBinding.cpp
@@ -238,7 +238,7 @@ bool ExpressionBinding::apply()
 {
     Property * prop(path.getProperty());
 
-    assert(prop != nullptr);
+    assert(prop);
     Q_UNUSED(prop);
 
     DocumentObject * docObj(path.getDocumentObject());
diff --git a/src/Gui/NavigationStyle.cpp b/src/Gui/NavigationStyle.cpp
index fff661220a..d19ae5987f 100644
--- a/src/Gui/NavigationStyle.cpp
+++ b/src/Gui/NavigationStyle.cpp
@@ -878,7 +878,7 @@ void NavigationStyle::spin(const SbVec2f & pointerpos)
 {
     if (this->log.historysize < 2)
         return;
-    assert(this->spinprojector != nullptr);
+    assert(this->spinprojector);
 
     const SbViewportRegion & vp = viewer->getSoRenderManager()->getViewportRegion();
     SbVec2s glsize(vp.getViewportSizePixels());
@@ -956,7 +956,7 @@ void NavigationStyle::spin(const SbVec2f & pointerpos)
  * \param prevpos  previous normalized position of mouse pointer
  */
 void NavigationStyle::spin_simplified(SoCamera* cam, SbVec2f curpos, SbVec2f prevpos){
-    assert(this->spinprojector != nullptr);
+    assert(this->spinprojector);
 
     // 0000333: Turntable camera rotation
     SbMatrix mat;
diff --git a/src/Gui/Quarter/QuarterP.cpp b/src/Gui/Quarter/QuarterP.cpp
index f540a85ac8..98a99b751a 100644
--- a/src/Gui/Quarter/QuarterP.cpp
+++ b/src/Gui/Quarter/QuarterP.cpp
@@ -43,7 +43,7 @@ QuarterP::QuarterP()
 {
   this->sensormanager = new SensorManager;
   this->imagereader = new ImageReader;
-  assert(QuarterP::statecursormap == nullptr);
+  assert(!QuarterP::statecursormap);
   QuarterP::statecursormap = new StateCursorMap;
 
 }
@@ -53,7 +53,7 @@ QuarterP::~QuarterP()
   delete this->imagereader;
   delete this->sensormanager;
 
-  assert(QuarterP::statecursormap != nullptr);
+  assert(QuarterP::statecursormap);
   delete QuarterP::statecursormap;
 
   // FIXME: Why not use an atexit mechanism for this?
diff --git a/src/Gui/SoFCOffscreenRenderer.cpp b/src/Gui/SoFCOffscreenRenderer.cpp
index 567000c970..d5f1a02e77 100644
--- a/src/Gui/SoFCOffscreenRenderer.cpp
+++ b/src/Gui/SoFCOffscreenRenderer.cpp
@@ -68,7 +68,7 @@ SoFCOffscreenRenderer* SoFCOffscreenRenderer::inst = nullptr;
 
 SoFCOffscreenRenderer& SoFCOffscreenRenderer::instance()
 {
-    if (inst==nullptr)
+    if (!inst)
         inst = new SoFCOffscreenRenderer(SbViewportRegion());
     return *inst;
 }
diff --git a/src/Gui/SoNavigationDragger.cpp b/src/Gui/SoNavigationDragger.cpp
index 5a9cc40a7e..86a172c1f6 100644
--- a/src/Gui/SoNavigationDragger.cpp
+++ b/src/Gui/SoNavigationDragger.cpp
@@ -165,9 +165,9 @@ RotTransDragger::RotTransDragger()
 
 RotTransDragger::~RotTransDragger()
 {
-   if (rotFieldSensor!=nullptr)
+   if (rotFieldSensor)
      delete rotFieldSensor;
-   if (translFieldSensor!=nullptr)
+   if (translFieldSensor)
      delete translFieldSensor;
 }
 
@@ -315,9 +315,9 @@ RotTransDragger::setUpConnections(SbBool onOff, SbBool doItAlways)
       unregisterChildDragger(ZD);
 
      // Disconnect the field sensors.
-     if (translFieldSensor->getAttachedField()!=nullptr)
+     if (translFieldSensor->getAttachedField())
         translFieldSensor->detach();
-     if (rotFieldSensor->getAttachedField()!=nullptr)
+     if (rotFieldSensor->getAttachedField())
         rotFieldSensor->detach();
 
      SoDragger::setUpConnections(onOff, doItAlways);
diff --git a/src/Gui/TaskView/TaskDialogPython.cpp b/src/Gui/TaskView/TaskDialogPython.cpp
index dd4643f3cf..5a6f06e862 100644
--- a/src/Gui/TaskView/TaskDialogPython.cpp
+++ b/src/Gui/TaskView/TaskDialogPython.cpp
@@ -128,7 +128,7 @@ Py::Object ControlPy::activeDialog(const Py::Tuple& args)
     if (!PyArg_ParseTuple(args.ptr(), ""))
         throw Py::Exception();
     Gui::TaskView::TaskDialog* dlg = Gui::Control().activeDialog();
-    return Py::Boolean(dlg!=nullptr);
+    return Py::Boolean(dlg != nullptr);
 }
 
 Py::Object ControlPy::closeDialog(const Py::Tuple& args)