diff --git a/src/Gui/MDIView.cpp b/src/Gui/MDIView.cpp
index ec427565f7..c24fa18ee1 100644
--- a/src/Gui/MDIView.cpp
+++ b/src/Gui/MDIView.cpp
@@ -226,12 +226,14 @@ void MDIView::closeEvent(QCloseEvent *e)
         // because otherwise other parts don't work as they should.
         QMainWindow::closeEvent(e);
     }
-    else
+    else {
         e->ignore();
+    }
 }
 
-void MDIView::windowStateChanged( MDIView* )
+void MDIView::windowStateChanged(QWidget* view)
 {
+    Q_UNUSED(view)
 }
 
 void MDIView::print(QPrinter* printer)
diff --git a/src/Gui/MDIView.h b/src/Gui/MDIView.h
index 86855a7242..724c2797ae 100644
--- a/src/Gui/MDIView.h
+++ b/src/Gui/MDIView.h
@@ -166,7 +166,7 @@ protected Q_SLOTS:
      * whenever the window state of the active view changes.
      * The default implementation does nothing.
      */
-    virtual void windowStateChanged(Gui::MDIView*);
+    virtual void windowStateChanged(QWidget*);
 
 protected:
     void closeEvent(QCloseEvent *e) override;
diff --git a/src/Gui/MainWindow.h b/src/Gui/MainWindow.h
index 4600ea85d1..dce8325d6d 100644
--- a/src/Gui/MainWindow.h
+++ b/src/Gui/MainWindow.h
@@ -347,7 +347,7 @@ private Q_SLOTS:
 
 Q_SIGNALS:
     void timeEvent();
-    void windowStateChanged(Gui::MDIView*);
+    void windowStateChanged(QWidget*);
     void workbenchActivated(const QString&);
     void mainWindowClosed();
 
diff --git a/src/Gui/PythonWrapper.cpp b/src/Gui/PythonWrapper.cpp
index c460d17bf9..412b56c47f 100644
--- a/src/Gui/PythonWrapper.cpp
+++ b/src/Gui/PythonWrapper.cpp
@@ -189,8 +189,7 @@ PythonToCppFunc toCppPointerCheckFuncQuantity(PyObject* obj)
 {
     if (PyObject_TypeCheck(obj, &(Base::QuantityPy::Type)))
         return toCppPointerConvFuncQuantity;
-    else
-        return nullptr;
+    return nullptr;
 }
 
 void BaseQuantity_PythonToCpp_QVariant(PyObject* pyIn, void* cppOut)
diff --git a/src/Gui/View3DInventor.cpp b/src/Gui/View3DInventor.cpp
index 9d4b8c0ea5..9d0244bf12 100644
--- a/src/Gui/View3DInventor.cpp
+++ b/src/Gui/View3DInventor.cpp
@@ -675,7 +675,7 @@ void View3DInventor::dump(const char* filename, bool onlyVisible)
     }
 }
 
-void View3DInventor::windowStateChanged(MDIView* view)
+void View3DInventor::windowStateChanged(QWidget* view)
 {
     bool canStartTimer = false;
     if (this != view) {
diff --git a/src/Gui/View3DInventor.h b/src/Gui/View3DInventor.h
index b11c3420b0..3bfe2b237a 100644
--- a/src/Gui/View3DInventor.h
+++ b/src/Gui/View3DInventor.h
@@ -125,7 +125,7 @@ private:
     void applySettings();
 
 protected:
-    void windowStateChanged(MDIView* ) override;
+    void windowStateChanged(QWidget* view) override;
     void dropEvent        (QDropEvent      * e) override;
     void dragEnterEvent   (QDragEnterEvent * e) override;
     void keyPressEvent    (QKeyEvent       * e) override;