diff --git a/src/App/Application.h b/src/App/Application.h
index 52b87fa0ff..91aa6d26e2 100644
--- a/src/App/Application.h
+++ b/src/App/Application.h
@@ -31,13 +31,15 @@
 
 #include <Base/Observer.h>
 #include <Base/Parameter.h>
-#include <Base/PyObjectBase.h>
 
+// forward declarations
+typedef struct _object PyObject;
+typedef struct PyMethodDef PyMethodDef;
 
 namespace Base
 {
-    class ConsoleObserverStd;
-    class ConsoleObserverFile;
+class ConsoleObserverStd;
+class ConsoleObserverFile;
 }
 
 namespace App
diff --git a/src/App/DocumentObjectExtension.h b/src/App/DocumentObjectExtension.h
index 9bcdeebff7..8b7ba82a39 100644
--- a/src/App/DocumentObjectExtension.h
+++ b/src/App/DocumentObjectExtension.h
@@ -25,8 +25,10 @@
 #define APP_DOCUMENTOBJECTEXTENSION_H
 
 #include "Extension.h"
-#include <Base/Matrix.h>
 
+namespace Base {
+class Matrix4D;
+}
 namespace App {
 class DocumentObject;
 class DocumentObjectExecReturn;
@@ -40,7 +42,7 @@ class AppExport DocumentObjectExtension : public App::Extension
 
     //The cass does not have properties itself, but it is important to provide the property access
     //functions. see cpp file for details
-    EXTENSION_PROPERTY_HEADER_WITH_OVERRIDE(App::DocumentObjectExtension );
+    EXTENSION_PROPERTY_HEADER_WITH_OVERRIDE(App::DocumentObjectExtension);
 
 public:
 
@@ -51,8 +53,8 @@ public:
     const App::DocumentObject* getExtendedObject() const;
 
     //override if execution is necessary
-    virtual short extensionMustExecute(void);
-    virtual App::DocumentObjectExecReturn *extensionExecute(void);
+    virtual short extensionMustExecute();
+    virtual App::DocumentObjectExecReturn *extensionExecute();
 
 
     /// get called after setting the document
@@ -64,18 +66,18 @@ public:
     /// get called when object is going to be removed from the document
     virtual void onExtendedUnsetupObject();
 
-    virtual PyObject* getExtensionPyObject(void) override;
+    virtual PyObject* getExtensionPyObject() override;
 
     /// returns the type name of the ViewProviderExtension which is automatically attached
     /// to the viewprovider object when it is initiated
-    virtual const char* getViewProviderExtensionName(void) const {return "";}
+    virtual const char* getViewProviderExtensionName() const {return "";}
 
     /** Get the sub object by name
      * @sa DocumentObject::getSubObject()
      *
      * @return Return turn if handled, the sub object is returned in \c ret
      */
-    virtual bool extensionGetSubObject( DocumentObject *&ret, const char *subname,
+    virtual bool extensionGetSubObject(DocumentObject *&ret, const char *subname,
         PyObject **pyObj, Base::Matrix4D *mat, bool transform, int depth) const;
 
     /** Get name references of all sub objects
diff --git a/src/App/DocumentObjectGroup.h b/src/App/DocumentObjectGroup.h
index fa658782d2..f0fa9301d3 100644
--- a/src/App/DocumentObjectGroup.h
+++ b/src/App/DocumentObjectGroup.h
@@ -38,15 +38,15 @@ class AppExport DocumentObjectGroup : public DocumentObject, public GroupExtensi
 
 public:
     /// Constructor
-    DocumentObjectGroup(void);
+    DocumentObjectGroup();
     virtual ~DocumentObjectGroup();
 
     /// returns the type name of the ViewProvider
-    virtual const char* getViewProviderName(void) const override{
+    virtual const char* getViewProviderName() const override {
         return "Gui::ViewProviderDocumentObjectGroup";
     }
 
-    virtual PyObject *getPyObject(void) override;
+    virtual PyObject *getPyObject() override;
 };
 
 typedef App::FeaturePythonT<DocumentObjectGroup> DocumentObjectGroupPython;
diff --git a/src/App/DocumentObserverPython.cpp b/src/App/DocumentObserverPython.cpp
index 3cf6bbaf3a..dbd197484f 100644
--- a/src/App/DocumentObserverPython.cpp
+++ b/src/App/DocumentObserverPython.cpp
@@ -23,6 +23,7 @@
 
 #include "PreCompiled.h"
 
+#include <CXX/Objects.hxx>
 #include "Application.h"
 #include "Document.h"
 #include "DocumentObject.h"
diff --git a/src/App/ExtensionContainer.cpp b/src/App/ExtensionContainer.cpp
index 6c0014c997..d3e233b48f 100644
--- a/src/App/ExtensionContainer.cpp
+++ b/src/App/ExtensionContainer.cpp
@@ -25,6 +25,8 @@
 
 #include <Base/Console.h>
 #include <Base/Exception.h>
+#include <Base/Reader.h>
+#include <Base/Writer.h>
 
 #include "Extension.h"
 #include "ExtensionContainer.h"
diff --git a/src/App/ExtensionContainer.h b/src/App/ExtensionContainer.h
index 1c36d98c01..30d28adecf 100644
--- a/src/App/ExtensionContainer.h
+++ b/src/App/ExtensionContainer.h
@@ -24,9 +24,6 @@
 #ifndef APP_EXTENSIONCONTAINER_H
 #define APP_EXTENSIONCONTAINER_H
 
-#include <Base/Reader.h>
-#include <Base/Writer.h>
-
 #include "PropertyContainer.h"
 
 
diff --git a/src/App/ObjectIdentifier.cpp b/src/App/ObjectIdentifier.cpp
index 78776739e8..9aab4afb81 100644
--- a/src/App/ObjectIdentifier.cpp
+++ b/src/App/ObjectIdentifier.cpp
@@ -34,6 +34,7 @@
 #include <Base/Interpreter.h>
 #include <Base/QuantityPy.h>
 #include <Base/Console.h>
+#include <Base/Reader.h>
 #include <CXX/Objects.hxx>
 
 #include "ObjectIdentifier.h"
diff --git a/src/App/Part.h b/src/App/Part.h
index c058582ebf..2ae9d33e44 100644
--- a/src/App/Part.h
+++ b/src/App/Part.h
@@ -76,11 +76,11 @@ public:
     //@}
 
     /// Constructor
-    Part(void);
+    Part();
     virtual ~Part();
 
     /// returns the type name of the ViewProvider
-    virtual const char* getViewProviderName(void) const override {
+    virtual const char* getViewProviderName() const override {
         return "Gui::ViewProviderPart";
     }
 
@@ -95,7 +95,7 @@ public:
      */
     static App::Part* getPartOfObject (const DocumentObject* obj, bool recursive=true);
 
-    virtual PyObject *getPyObject(void) override;
+    virtual PyObject *getPyObject() override;
 };
 
 //typedef App::FeaturePythonT<Part> PartPython;
diff --git a/src/App/PropertyExpressionEngine.cpp b/src/App/PropertyExpressionEngine.cpp
index 858073d5b9..9cdd282b34 100644
--- a/src/App/PropertyExpressionEngine.cpp
+++ b/src/App/PropertyExpressionEngine.cpp
@@ -28,6 +28,7 @@
 #include <Base/Reader.h>
 #include <Base/Tools.h>
 #include <Base/Writer.h>
+#include <CXX/Objects.hxx>
 
 #include "PropertyExpressionEngine.h"
 #include "ExpressionVisitors.h"
diff --git a/src/Gui/ApplicationPy.cpp b/src/Gui/ApplicationPy.cpp
index a1bbd4bb4e..8861a821ee 100644
--- a/src/Gui/ApplicationPy.cpp
+++ b/src/Gui/ApplicationPy.cpp
@@ -31,6 +31,7 @@
 # include <Inventor/SoInput.h>
 # include <Inventor/actions/SoGetPrimitiveCountAction.h>
 # include <Inventor/nodes/SoSeparator.h>
+# include <xercesc/util/XMLString.hpp>
 #endif
 
 #include <boost/regex.hpp>
diff --git a/src/Gui/Tree.cpp b/src/Gui/Tree.cpp
index dd3c55cd90..7f38a391c4 100644
--- a/src/Gui/Tree.cpp
+++ b/src/Gui/Tree.cpp
@@ -40,8 +40,10 @@
 #endif
 
 #include <Base/Console.h>
+#include <Base/Reader.h>
 #include <Base/Sequencer.h>
 #include <Base/Tools.h>
+#include <Base/Writer.h>
 
 #include <App/DocumentObjectGroup.h>
 #include <App/AutoTransaction.h>
diff --git a/src/Main/FreeCADGuiPy.cpp b/src/Main/FreeCADGuiPy.cpp
index 165493d682..23de8300b5 100644
--- a/src/Main/FreeCADGuiPy.cpp
+++ b/src/Main/FreeCADGuiPy.cpp
@@ -44,6 +44,7 @@
 #include <Base/Exception.h>
 #include <Base/Factory.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/BitmapFactory.h>
 #include <Gui/MainWindow.h>
diff --git a/src/Main/MainPy.cpp b/src/Main/MainPy.cpp
index 739deb9afc..941451789b 100644
--- a/src/Main/MainPy.cpp
+++ b/src/Main/MainPy.cpp
@@ -47,6 +47,7 @@
 
 // FreeCAD Base header
 #include <Base/Exception.h>
+#include <Base/PyObjectBase.h>
 #include <Base/Sequencer.h>
 #include <App/Application.h>
 
diff --git a/src/Mod/Drawing/Gui/AppDrawingGui.cpp b/src/Mod/Drawing/Gui/AppDrawingGui.cpp
index 352ce705a6..5e940cb25c 100644
--- a/src/Mod/Drawing/Gui/AppDrawingGui.cpp
+++ b/src/Mod/Drawing/Gui/AppDrawingGui.cpp
@@ -27,6 +27,7 @@
 #endif
 
 #include <Base/Console.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include "Workbench.h"
diff --git a/src/Mod/Fem/App/PropertyPostDataObject.cpp b/src/Mod/Fem/App/PropertyPostDataObject.cpp
index db6dbb803d..cccf9febd9 100644
--- a/src/Mod/Fem/App/PropertyPostDataObject.cpp
+++ b/src/Mod/Fem/App/PropertyPostDataObject.cpp
@@ -47,6 +47,7 @@
 #include <Base/Reader.h>
 #include <App/Application.h>
 #include <App/DocumentObject.h>
+#include <CXX/Objects.hxx>
 
 #include "PropertyPostDataObject.h"
 
diff --git a/src/Mod/Fem/Gui/AppFemGui.cpp b/src/Mod/Fem/Gui/AppFemGui.cpp
index 302a161f6f..ce35802eca 100644
--- a/src/Mod/Fem/Gui/AppFemGui.cpp
+++ b/src/Mod/Fem/Gui/AppFemGui.cpp
@@ -29,6 +29,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/WidgetFactory.h>
 #include <Gui/Language/Translator.h>
diff --git a/src/Mod/Image/Gui/AppImageGui.cpp b/src/Mod/Image/Gui/AppImageGui.cpp
index 170ee8b3bc..7a8db012ef 100644
--- a/src/Mod/Image/Gui/AppImageGui.cpp
+++ b/src/Mod/Image/Gui/AppImageGui.cpp
@@ -16,6 +16,7 @@
 #endif
 
 #include <Base/Console.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include "ImageView.h"
diff --git a/src/Mod/Import/Gui/AppImportGui.cpp b/src/Mod/Import/Gui/AppImportGui.cpp
index 1a7d7c1ead..0f135c754e 100644
--- a/src/Mod/Import/Gui/AppImportGui.cpp
+++ b/src/Mod/Import/Gui/AppImportGui.cpp
@@ -29,6 +29,7 @@
 #include <App/Application.h>
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 
 #include <Gui/Application.h>
 
diff --git a/src/Mod/Inspection/Gui/AppInspectionGui.cpp b/src/Mod/Inspection/Gui/AppInspectionGui.cpp
index dcb5fe6690..7624e77b6b 100644
--- a/src/Mod/Inspection/Gui/AppInspectionGui.cpp
+++ b/src/Mod/Inspection/Gui/AppInspectionGui.cpp
@@ -30,6 +30,7 @@
 #include <CXX/Objects.hxx>
 
 #include <Base/Console.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 
 #include "ViewProviderInspection.h"
diff --git a/src/Mod/Mesh/Gui/AppMeshGui.cpp b/src/Mod/Mesh/Gui/AppMeshGui.cpp
index dbd8f721fa..d32a183aeb 100644
--- a/src/Mod/Mesh/Gui/AppMeshGui.cpp
+++ b/src/Mod/Mesh/Gui/AppMeshGui.cpp
@@ -31,6 +31,7 @@
 
 #include <Base/Interpreter.h>
 #include <Base/Console.h>
+#include <Base/PyObjectBase.h>
 
 #include <CXX/Extensions.hxx>
 #include <CXX/Objects.hxx>
diff --git a/src/Mod/MeshPart/Gui/AppMeshPartGui.cpp b/src/Mod/MeshPart/Gui/AppMeshPartGui.cpp
index 64aa198feb..ed41f742af 100644
--- a/src/Mod/MeshPart/Gui/AppMeshPartGui.cpp
+++ b/src/Mod/MeshPart/Gui/AppMeshPartGui.cpp
@@ -30,6 +30,7 @@
 #include <CXX/Objects.hxx>
 
 #include <Base/Console.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include "CurveOnMesh.h"
diff --git a/src/Mod/Part/Gui/AppPartGui.cpp b/src/Mod/Part/Gui/AppPartGui.cpp
index d0ad1f3581..bca7e39503 100644
--- a/src/Mod/Part/Gui/AppPartGui.cpp
+++ b/src/Mod/Part/Gui/AppPartGui.cpp
@@ -18,6 +18,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/BitmapFactory.h>
 #include <Gui/WidgetFactory.h>
diff --git a/src/Mod/PartDesign/Gui/AppPartDesignGui.cpp b/src/Mod/PartDesign/Gui/AppPartDesignGui.cpp
index 54b08fe1d5..e829595278 100644
--- a/src/Mod/PartDesign/Gui/AppPartDesignGui.cpp
+++ b/src/Mod/PartDesign/Gui/AppPartDesignGui.cpp
@@ -31,6 +31,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 
diff --git a/src/Mod/Path/Gui/AppPathGui.cpp b/src/Mod/Path/Gui/AppPathGui.cpp
index 994d11df6c..83664ee97a 100644
--- a/src/Mod/Path/Gui/AppPathGui.cpp
+++ b/src/Mod/Path/Gui/AppPathGui.cpp
@@ -28,6 +28,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/WidgetFactory.h>
 #include <Gui/Language/Translator.h>
diff --git a/src/Mod/Points/Gui/AppPointsGui.cpp b/src/Mod/Points/Gui/AppPointsGui.cpp
index c8beabcddb..ef62f742b8 100644
--- a/src/Mod/Points/Gui/AppPointsGui.cpp
+++ b/src/Mod/Points/Gui/AppPointsGui.cpp
@@ -33,6 +33,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include <Mod/Points/App/PropertyPointKernel.h>
diff --git a/src/Mod/Raytracing/Gui/AppRaytracingGui.cpp b/src/Mod/Raytracing/Gui/AppRaytracingGui.cpp
index 182ad51442..058da3b834 100644
--- a/src/Mod/Raytracing/Gui/AppRaytracingGui.cpp
+++ b/src/Mod/Raytracing/Gui/AppRaytracingGui.cpp
@@ -25,6 +25,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/WidgetFactory.h>
 #include <Gui/Language/Translator.h>
diff --git a/src/Mod/ReverseEngineering/Gui/AppReverseEngineeringGui.cpp b/src/Mod/ReverseEngineering/Gui/AppReverseEngineeringGui.cpp
index 7317655970..b5ad5bad23 100644
--- a/src/Mod/ReverseEngineering/Gui/AppReverseEngineeringGui.cpp
+++ b/src/Mod/ReverseEngineering/Gui/AppReverseEngineeringGui.cpp
@@ -28,6 +28,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include "Workbench.h"
diff --git a/src/Mod/Robot/Gui/AppRobotGui.cpp b/src/Mod/Robot/Gui/AppRobotGui.cpp
index fe39f49072..96ade4ef97 100644
--- a/src/Mod/Robot/Gui/AppRobotGui.cpp
+++ b/src/Mod/Robot/Gui/AppRobotGui.cpp
@@ -31,6 +31,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/Language/Translator.h>
 #include "ViewProviderRobotObject.h"
diff --git a/src/Mod/Sketcher/Gui/AppSketcherGui.cpp b/src/Mod/Sketcher/Gui/AppSketcherGui.cpp
index c0e2931128..678c46ab71 100644
--- a/src/Mod/Sketcher/Gui/AppSketcherGui.cpp
+++ b/src/Mod/Sketcher/Gui/AppSketcherGui.cpp
@@ -31,6 +31,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/BitmapFactory.h>
 #include <Gui/Language/Translator.h>
diff --git a/src/Mod/Spreadsheet/Gui/SheetTableView.cpp b/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
index c2564abc4f..f0089132df 100644
--- a/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
+++ b/src/Mod/Spreadsheet/Gui/SheetTableView.cpp
@@ -37,6 +37,8 @@
 #include <App/Application.h>
 #include <App/AutoTransaction.h>
 #include <App/Document.h>
+#include <Base/Reader.h>
+#include <Base/Writer.h>
 #include <Gui/CommandT.h>
 #include <Gui/Application.h>
 #include <Gui/MainWindow.h>
diff --git a/src/Mod/Start/Gui/AppStartGui.cpp b/src/Mod/Start/Gui/AppStartGui.cpp
index 304d984b1e..f1df14bab2 100644
--- a/src/Mod/Start/Gui/AppStartGui.cpp
+++ b/src/Mod/Start/Gui/AppStartGui.cpp
@@ -31,6 +31,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/WorkbenchManager.h>
 #include <Gui/Language/Translator.h>
diff --git a/src/Mod/TechDraw/Gui/mrichtextedit.h b/src/Mod/TechDraw/Gui/mrichtextedit.h
index 28a8bf5859..0e81846fe5 100644
--- a/src/Mod/TechDraw/Gui/mrichtextedit.h
+++ b/src/Mod/TechDraw/Gui/mrichtextedit.h
@@ -52,14 +52,14 @@ class MRichTextEdit : public QWidget, protected Ui::MRichTextEdit {
     int getDefFontSizeNum(void);
     QFont getDefFont(void);
    
-  public slots:
+  public Q_SLOTS:
     void setText(const QString &text);
 
 Q_SIGNALS:
     void saveText(QString revText);
     void editorFinished();
 
-  protected slots:
+  protected Q_SLOTS:
     void onSave(void);
     void onExit(void);
     void setPlainText(const QString &text) { f_textedit->setPlainText(text); }
diff --git a/src/Mod/Web/Gui/AppWebGui.cpp b/src/Mod/Web/Gui/AppWebGui.cpp
index f48928d97a..fdb3e4b39d 100644
--- a/src/Mod/Web/Gui/AppWebGui.cpp
+++ b/src/Mod/Web/Gui/AppWebGui.cpp
@@ -32,6 +32,7 @@
 
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
+#include <Base/PyObjectBase.h>
 #include <Gui/Application.h>
 #include <Gui/MainWindow.h>
 #include <Gui/WorkbenchManager.h>