diff --git a/src/App/ApplicationPy.cpp b/src/App/ApplicationPy.cpp
index 96793ee80e..773d25add3 100644
--- a/src/App/ApplicationPy.cpp
+++ b/src/App/ApplicationPy.cpp
@@ -100,9 +100,9 @@ PyMethodDef Application::Methods[] = {
      "* If no module is given it will be determined by the file extension.\n"
      "* If more than one module can load a file the first one will be taken.\n"
      "* If no module exists to load the file an exception will be raised."},
-    {"open",   reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) (void)>( Application::sOpenDocument )), METH_VARARGS|METH_KEYWORDS,
+    {"open",   reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) ()>( Application::sOpenDocument )), METH_VARARGS|METH_KEYWORDS,
      "See openDocument(string)"},
-    {"openDocument",   reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) (void)>( Application::sOpenDocument )), METH_VARARGS|METH_KEYWORDS,
+    {"openDocument",   reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) ()>( Application::sOpenDocument )), METH_VARARGS|METH_KEYWORDS,
      "openDocument(filepath,hidden=False) -> object\n"
      "Create a document and load the project file into the document.\n\n"
      "filepath: file path to an existing file. If the file doesn't exist\n"
@@ -112,7 +112,7 @@ PyMethodDef Application::Methods[] = {
 //  {"saveDocument",   (PyCFunction) Application::sSaveDocument, METH_VARARGS,
 //   "saveDocument(string) -- Save the document to a file."},
 //  {"saveDocumentAs", (PyCFunction) Application::sSaveDocumentAs, METH_VARARGS},
-    {"newDocument",    reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) (void)>( Application::sNewDocument )), METH_VARARGS|METH_KEYWORDS,
+    {"newDocument",    reinterpret_cast<PyCFunction>(reinterpret_cast<void (*) ()>( Application::sNewDocument )), METH_VARARGS|METH_KEYWORDS,
      "newDocument(name, label=None, hidden=False, temp=False) -> object\n"
      "Create a new document with a given name.\n\n"
      "name: unique document name which is checked automatically.\n"
diff --git a/src/App/DocumentObject.h b/src/App/DocumentObject.h
index f7f0772566..2ff1a3fd23 100644
--- a/src/App/DocumentObject.h
+++ b/src/App/DocumentObject.h
@@ -112,7 +112,7 @@ public:
     boost::signals2::signal<void (const App::DocumentObject&, const App::Property&)> signalChanged;
 
     /// returns the type name of the ViewProvider
-    virtual const char* getViewProviderName(void) const {
+    virtual const char* getViewProviderName() const {
         return "";
     }
     /**
@@ -129,11 +129,11 @@ public:
     }
 
     /// Constructor
-    DocumentObject(void);
+    DocumentObject();
     virtual ~DocumentObject();
 
     /// returns the name which is set in the document for this object (not the name property!)
-    const char *getNameInDocument(void) const;
+    const char *getNameInDocument() const;
     /// Return the object ID that is unique within its owner document
     long getID() const {return _Id;}
     /// returns the name that is safe to be exported to other document
@@ -143,7 +143,7 @@ public:
     virtual bool isAttachedToDocument() const override;
     virtual const char* detachFromDocument() override;
     /// gets the document in which this Object is handled
-    App::Document *getDocument(void) const;
+    App::Document *getDocument() const;
 
     /** Set the property touched -> changed, cause recomputation in Update()
      */
@@ -151,22 +151,22 @@ public:
     /// set this document object touched (cause recomputation on dependent features)
     void touch(bool noRecompute=false);
     /// test if this document object is touched
-    bool isTouched(void) const;
+    bool isTouched() const;
     /// Enforce this document object to be recomputed
     void enforceRecompute();
     /// Test if this document object must be recomputed
-    bool mustRecompute(void) const;
+    bool mustRecompute() const;
     /// reset this document object touched
-    void purgeTouched(void) {
+    void purgeTouched() {
         StatusBits.reset(ObjectStatus::Touch);
         StatusBits.reset(ObjectStatus::Enforce);
         setPropertyStatus(0,false);
     }
     /// set this feature to error
-    bool isError(void) const {return  StatusBits.test(ObjectStatus::Error);}
-    bool isValid(void) const {return !StatusBits.test(ObjectStatus::Error);}
+    bool isError() const {return  StatusBits.test(ObjectStatus::Error);}
+    bool isValid() const {return !StatusBits.test(ObjectStatus::Error);}
     /// remove the error from the object
-    void purgeError(void){StatusBits.reset(ObjectStatus::Error);}
+    void purgeError(){StatusBits.reset(ObjectStatus::Error);}
     /// returns true if this objects is currently recomputing
     bool isRecomputing() const {return StatusBits.test(ObjectStatus::Recompute);}
     /// returns true if this objects is currently restoring from file
@@ -228,7 +228,7 @@ public:
     /// returns a list of objects linked by the property
     std::vector<App::DocumentObject*> getOutListOfProperty(App::Property*) const;
     /// returns a list of objects this object is pointing to by Links and all further descended
-    std::vector<App::DocumentObject*> getOutListRecursive(void) const;
+    std::vector<App::DocumentObject*> getOutListRecursive() const;
     /// clear internal out list cache
     void clearOutListCache() const;
     /// get all possible paths from this to another object following the OutList
@@ -237,10 +237,10 @@ public:
     /// get all objects link to this object
     std::vector<App::DocumentObject*> getInList(void) const
 #else
-    const std::vector<App::DocumentObject*> &getInList(void) const;
+    const std::vector<App::DocumentObject*> &getInList() const;
 #endif
     /// get all objects link directly or indirectly to this object
-    std::vector<App::DocumentObject*> getInListRecursive(void) const;
+    std::vector<App::DocumentObject*> getInListRecursive() const;
     /** Get a set of all objects linking to this object, including possible external parent objects
      *
      * @param inSet [out]: a set containing all objects linking to this object.
@@ -299,7 +299,7 @@ public:
      * necessarily mean that it will be recomputed. It only means that all
      * objects that link it (i.e. its InList) will be recomputed.
      */
-    virtual short mustExecute(void) const;
+    virtual short mustExecute() const;
 
     /** Recompute only this feature
      *
@@ -308,7 +308,7 @@ public:
     bool recomputeFeature(bool recursive=false);
 
     /// get the status Message
-    const char *getStatusString(void) const;
+    const char *getStatusString() const;
 
     /** Called in case of losing a link
      * Get called by the document when a object got deleted a link property of this
@@ -317,7 +317,7 @@ public:
      * additional or different behavior.
      */
     virtual void onLostLinkToObject(DocumentObject*);
-    virtual PyObject *getPyObject(void) override;
+    virtual PyObject *getPyObject() override;
 
     /** Get the sub element/object by name
      *
@@ -561,7 +561,7 @@ public:
 
 protected:
     /// recompute only this object
-    virtual App::DocumentObjectExecReturn *recompute(void);
+    virtual App::DocumentObjectExecReturn *recompute();
     /** get called by the document to recompute this feature
       * Normally this method get called in the processing of
       * Document::recompute().
@@ -569,7 +569,7 @@ protected:
       * with the data from linked objects and objects own
       * properties.
       */
-    virtual App::DocumentObjectExecReturn *execute(void);
+    virtual App::DocumentObjectExecReturn *execute();
 
     /**
      * Executes the extensions of a document object.
@@ -592,8 +592,8 @@ protected:
      */
     std::bitset<32> StatusBits;
 
-    void setError(void){StatusBits.set(ObjectStatus::Error);}
-    void resetError(void){StatusBits.reset(ObjectStatus::Error);}
+    void setError(){StatusBits.set(ObjectStatus::Error);}
+    void resetError(){StatusBits.reset(ObjectStatus::Error);}
     void setDocument(App::Document* doc);
 
     /// get called before the value is changed
diff --git a/src/App/Expression.cpp b/src/App/Expression.cpp
index e4c5f48598..844db1c6b0 100644
--- a/src/App/Expression.cpp
+++ b/src/App/Expression.cpp
@@ -3191,7 +3191,7 @@ static int column;
 
 // show the parser the lexer method
 #define yylex ExpressionParserlex
-int ExpressionParserlex(void);
+int ExpressionParserlex();
 
 // Parser, defined in ExpressionParser.y
 # define YYTOKENTYPE
diff --git a/src/App/Link.cpp b/src/App/Link.cpp
index 270cc30b73..e8ba3f06d3 100644
--- a/src/App/Link.cpp
+++ b/src/App/Link.cpp
@@ -148,7 +148,7 @@ void LinkParams::removeCopyOnChangeApplyToAll() {
 
 EXTENSION_PROPERTY_SOURCE(App::LinkBaseExtension, App::DocumentObjectExtension)
 
-LinkBaseExtension::LinkBaseExtension(void)
+LinkBaseExtension::LinkBaseExtension()
     :enableLabelCache(false),hasOldSubElement(false),hasCopyOnChange(true)
 {
     initExtensionType(LinkBaseExtension::getExtensionClassTypeId());
@@ -166,7 +166,7 @@ LinkBaseExtension::~LinkBaseExtension()
 {
 }
 
-PyObject* LinkBaseExtension::getExtensionPyObject(void) {
+PyObject* LinkBaseExtension::getExtensionPyObject() {
     if (ExtensionPythonObject.is(Py::_None())){
         // ref counter is set to 1
         ExtensionPythonObject = Py::Object(new LinkBaseExtensionPy(this),true);
@@ -293,7 +293,7 @@ void LinkBaseExtension::setProperty(int idx, Property *prop) {
 
 static const char _GroupPrefix[] = "Configuration (";
 
-App::DocumentObjectExecReturn *LinkBaseExtension::extensionExecute(void) {
+App::DocumentObjectExecReturn *LinkBaseExtension::extensionExecute() {
     // The actual value of LinkTouched is not important, just to notify view
     // provider that the link (in fact, its dependents, i.e. linked ones) have
     // recomputed.
@@ -398,7 +398,7 @@ App::DocumentObjectExecReturn *LinkBaseExtension::extensionExecute(void) {
     return inherited::extensionExecute();
 }
 
-short LinkBaseExtension::extensionMustExecute(void) {
+short LinkBaseExtension::extensionMustExecute() {
     auto link = getLink();
     if(!link)
         return 0;
@@ -2225,7 +2225,7 @@ template class AppExport ExtensionPythonT<LinkBaseExtension>;
 
 EXTENSION_PROPERTY_SOURCE(App::LinkExtension, App::LinkBaseExtension)
 
-LinkExtension::LinkExtension(void)
+LinkExtension::LinkExtension()
 {
     initExtensionType(LinkExtension::getExtensionClassTypeId());
 
@@ -2265,7 +2265,7 @@ bool Link::canLinkProperties() const {
 
 namespace App {
 PROPERTY_SOURCE_TEMPLATE(App::LinkPython, App::Link)
-template<> const char* App::LinkPython::getViewProviderName(void) const {
+template<> const char* App::LinkPython::getViewProviderName() const {
     return "Gui::ViewProviderLinkPython";
 }
 template class AppExport FeaturePythonT<App::Link>;
@@ -2292,7 +2292,7 @@ bool LinkElement::canDelete() const {
 
 namespace App {
 PROPERTY_SOURCE_TEMPLATE(App::LinkElementPython, App::LinkElement)
-template<> const char* App::LinkElementPython::getViewProviderName(void) const {
+template<> const char* App::LinkElementPython::getViewProviderName() const {
     return "Gui::ViewProviderLinkPython";
 }
 template class AppExport FeaturePythonT<App::LinkElement>;
@@ -2311,7 +2311,7 @@ LinkGroup::LinkGroup() {
 
 namespace App {
 PROPERTY_SOURCE_TEMPLATE(App::LinkGroupPython, App::LinkGroup)
-template<> const char* App::LinkGroupPython::getViewProviderName(void) const {
+template<> const char* App::LinkGroupPython::getViewProviderName() const {
     return "Gui::ViewProviderLinkPython";
 }
 template class AppExport FeaturePythonT<App::LinkGroup>;
diff --git a/src/App/Link.h b/src/App/Link.h
index 60757cc725..1d3001fbad 100644
--- a/src/App/Link.h
+++ b/src/App/Link.h
@@ -286,8 +286,8 @@ public:
     bool extensionGetLinkedObject(DocumentObject *&ret,
             bool recurse, Base::Matrix4D *mat, bool transform, int depth) const override;
 
-    virtual App::DocumentObjectExecReturn *extensionExecute(void) override;
-    virtual short extensionMustExecute(void) override;
+    virtual App::DocumentObjectExecReturn *extensionExecute() override;
+    virtual short extensionMustExecute() override;
     virtual void extensionOnChanged(const Property* p) override;
     virtual void onExtendedUnsetupObject () override;
     virtual void onExtendedDocumentRestored() override;
@@ -296,7 +296,7 @@ public:
     virtual int extensionIsElementVisible(const char *) override;
     virtual bool extensionHasChildElement() const override;
 
-    virtual PyObject* getExtensionPyObject(void) override;
+    virtual PyObject* getExtensionPyObject() override;
 
     virtual Property *extensionGetPropertyByName(const char* name) const override;
 
@@ -536,9 +536,9 @@ public:
 
     LINK_PROPS_DEFINE(LINK_PARAMS_LINK)
 
-    Link(void);
+    Link();
 
-    const char* getViewProviderName(void) const override{
+    const char* getViewProviderName() const override{
         return "Gui::ViewProviderLink";
     }
 
@@ -581,7 +581,7 @@ public:
     LINK_PROPS_DEFINE(LINK_PARAMS_ELEMENT)
 
     LinkElement();
-    const char* getViewProviderName(void) const override{
+    const char* getViewProviderName() const override{
         return "Gui::ViewProviderLink";
     }
 
@@ -620,7 +620,7 @@ public:
 
     LinkGroup();
 
-    const char* getViewProviderName(void) const override{
+    const char* getViewProviderName() const override{
         return "Gui::ViewProviderLink";
     }