diff --git a/src/App/Application.cpp b/src/App/Application.cpp
index 7b7aee0f8b..8d538d2485 100644
--- a/src/App/Application.cpp
+++ b/src/App/Application.cpp
@@ -3177,8 +3177,8 @@ void Application::ExtractUserPath()
 }
 
 #if defined (FC_OS_LINUX) || defined(FC_OS_CYGWIN) || defined(FC_OS_BSD)
-#include <stdio.h>
-#include <stdlib.h>
+#include <cstdio>
+#include <cstdlib>
 #include <sys/param.h>
 
 std::string Application::FindHomePath(const char* sCall)
@@ -3235,7 +3235,7 @@ std::string Application::FindHomePath(const char* sCall)
 #elif defined(FC_OS_MACOSX)
 #include <mach-o/dyld.h>
 #include <string>
-#include <stdlib.h>
+#include <cstdlib>
 #include <sys/param.h>
 
 std::string Application::FindHomePath(const char* call)
diff --git a/src/App/ComplexGeoData.h b/src/App/ComplexGeoData.h
index f989f190e9..81ae1e347e 100644
--- a/src/App/ComplexGeoData.h
+++ b/src/App/ComplexGeoData.h
@@ -29,7 +29,7 @@
 #include <Base/Persistence.h>
 
 #ifdef __GNUC__
-# include <stdint.h>
+# include <cstdint>
 #endif
 
 
diff --git a/src/Base/MemDebug.cpp b/src/Base/MemDebug.cpp
index 99a1e6ce19..d75150d1d7 100644
--- a/src/Base/MemDebug.cpp
+++ b/src/Base/MemDebug.cpp
@@ -41,7 +41,7 @@
 
 #ifndef _PreComp_
 # ifdef _MSC_VER
-#  include <time.h>
+#  include <ctime>
 #  include <crtdbg.h>
 # endif
 #endif
diff --git a/src/Base/PreCompiled.h b/src/Base/PreCompiled.h
index fa931dfe0a..4faa87df2d 100644
--- a/src/Base/PreCompiled.h
+++ b/src/Base/PreCompiled.h
@@ -35,7 +35,7 @@
 #include <fcntl.h>
 #include <cstdio>
 #include <cassert>
-#include <time.h>
+#include <ctime>
 #include <cfloat>
 #ifdef FC_OS_WIN32
 #define _USE_MATH_DEFINES
diff --git a/src/Gui/GuiApplication.cpp b/src/Gui/GuiApplication.cpp
index 7b177e61d0..a39f5d2ab3 100644
--- a/src/Gui/GuiApplication.cpp
+++ b/src/Gui/GuiApplication.cpp
@@ -41,7 +41,7 @@
 
 #if defined(Q_OS_UNIX)
 # include <sys/types.h>
-# include <time.h>
+# include <ctime>
 # include <unistd.h>
 #endif
 
diff --git a/src/Gui/Macro.cpp b/src/Gui/Macro.cpp
index fc44a2ccb6..9d5fc5a711 100644
--- a/src/Gui/Macro.cpp
+++ b/src/Gui/Macro.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-# include <assert.h>
+# include <cassert>
 # include <QFile>
 # include <QTextStream>
 #endif
diff --git a/src/Gui/NaviCube.cpp b/src/Gui/NaviCube.cpp
index f36624c2cb..d3106df764 100644
--- a/src/Gui/NaviCube.cpp
+++ b/src/Gui/NaviCube.cpp
@@ -23,7 +23,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-# include <float.h>
+# include <cfloat>
 # ifdef FC_OS_WIN32
 #  include <windows.h>
 # endif
diff --git a/src/Gui/PreCompiled.h b/src/Gui/PreCompiled.h
index 81f030f8bb..d56b005c11 100644
--- a/src/Gui/PreCompiled.h
+++ b/src/Gui/PreCompiled.h
@@ -45,13 +45,13 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <fcntl.h>
-#include <ctype.h>
+#include <cctype>
 #include <typeinfo>
-#include <float.h>
-#include <limits.h>
+#include <cfloat>
+#include <climits>
 
 #ifdef FC_OS_WIN32
 #include <Windows.h>
@@ -59,9 +59,6 @@
 #include <shellapi.h>
 #endif
 
-// null-terminated byte string
-#include <cctype>
-
 // streams
 #include <iostream>
 #include <iomanip>
diff --git a/src/Gui/SoFCCSysDragger.cpp b/src/Gui/SoFCCSysDragger.cpp
index 8983e65992..55ddf27c3f 100644
--- a/src/Gui/SoFCCSysDragger.cpp
+++ b/src/Gui/SoFCCSysDragger.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 
 #include <Inventor/SbRotation.h>
 #include <Inventor/actions/SoGLRenderAction.h>
diff --git a/src/Gui/TaskCSysDragger.cpp b/src/Gui/TaskCSysDragger.cpp
index 269a2a2e43..244b5e2f53 100644
--- a/src/Gui/TaskCSysDragger.cpp
+++ b/src/Gui/TaskCSysDragger.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <limits>
 #include <QApplication>
 #include <QGridLayout>
diff --git a/src/Gui/View3DInventorViewer.cpp b/src/Gui/View3DInventorViewer.cpp
index cf44cd10ab..6454627033 100644
--- a/src/Gui/View3DInventorViewer.cpp
+++ b/src/Gui/View3DInventorViewer.cpp
@@ -23,7 +23,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-# include <float.h>
+# include <cfloat>
 # ifdef FC_OS_WIN32
 #  include <windows.h>
 # endif
diff --git a/src/Main/MainCmd.cpp b/src/Main/MainCmd.cpp
index 5631ca97c8..f1e8ad7e88 100644
--- a/src/Main/MainCmd.cpp
+++ b/src/Main/MainCmd.cpp
@@ -35,7 +35,7 @@
 # include <config.h>
 #endif // HAVE_CONFIG_H
 
-#include <stdio.h>
+#include <cstdio>
 #include <sstream>
 
 // FreeCAD Base header
diff --git a/src/Main/MainPy.cpp b/src/Main/MainPy.cpp
index 52af2ad59a..9149476dfd 100644
--- a/src/Main/MainPy.cpp
+++ b/src/Main/MainPy.cpp
@@ -40,7 +40,7 @@
 # include <config.h>
 #endif // HAVE_CONFIG_H
 
-#include <stdio.h>
+#include <cstdio>
 #include <sstream>
 #include <iostream>
 
diff --git a/src/Mod/Cloud/App/AppCloud.cpp b/src/Mod/Cloud/App/AppCloud.cpp
index 5703e84427..c3ddb75131 100644
--- a/src/Mod/Cloud/App/AppCloud.cpp
+++ b/src/Mod/Cloud/App/AppCloud.cpp
@@ -24,7 +24,7 @@
 
 #if defined(FC_OS_WIN32)
 #include <Windows.h>
-#include <stdint.h>
+#include <cstdint>
 #endif
 
 #include <openssl/hmac.h>
diff --git a/src/Mod/Draft/App/PreCompiled.h b/src/Mod/Draft/App/PreCompiled.h
index 0922240f4d..db5ddde744 100644
--- a/src/Mod/Draft/App/PreCompiled.h
+++ b/src/Mod/Draft/App/PreCompiled.h
@@ -44,8 +44,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Drawing/App/PreCompiled.h b/src/Mod/Drawing/App/PreCompiled.h
index fe8b73dee9..a8bde9ce7c 100644
--- a/src/Mod/Drawing/App/PreCompiled.h
+++ b/src/Mod/Drawing/App/PreCompiled.h
@@ -44,8 +44,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Fem/App/FemConstraint.cpp b/src/Mod/Fem/App/FemConstraint.cpp
index 21513c9b99..98ecdd52ca 100644
--- a/src/Mod/Fem/App/FemConstraint.cpp
+++ b/src/Mod/Fem/App/FemConstraint.cpp
@@ -25,7 +25,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-# include <math.h> //OvG: Required for log10
+# include <cmath> //OvG: Required for log10
 # include <TopoDS.hxx>
 # include <BRepGProp_Face.hxx>
 # include <gp_Vec.hxx>
diff --git a/src/Mod/Fem/App/PreCompiled.h b/src/Mod/Fem/App/PreCompiled.h
index cdb354386c..d1900c999a 100644
--- a/src/Mod/Fem/App/PreCompiled.h
+++ b/src/Mod/Fem/App/PreCompiled.h
@@ -49,8 +49,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
@@ -60,8 +60,6 @@
 #include <memory>
 #include <cmath>
 
-#include <math.h>
-
 #include <algorithm>
 #include <stdexcept>
 
diff --git a/src/Mod/Fem/Gui/PreCompiled.h b/src/Mod/Fem/Gui/PreCompiled.h
index caa666e457..76b59621c5 100644
--- a/src/Mod/Fem/Gui/PreCompiled.h
+++ b/src/Mod/Fem/Gui/PreCompiled.h
@@ -48,7 +48,7 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 #include <math.h>
diff --git a/src/Mod/Fem/Gui/ViewProviderFemConstraintTransform.cpp b/src/Mod/Fem/Gui/ViewProviderFemConstraintTransform.cpp
index 53a169addf..3054cd1cd2 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemConstraintTransform.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemConstraintTransform.cpp
@@ -44,7 +44,7 @@
 # include <Inventor/nodes/SoMaterialBinding.h>
 # include <Inventor/nodes/SoScale.h>
 
-# include <math.h>
+# include <cmath>
 #endif
 
 #include <Gui/Command.h>
diff --git a/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp b/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
index de6d0550b6..d1472dd05c 100644
--- a/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
+++ b/src/Mod/Fem/Gui/ViewProviderFemPostFunction.cpp
@@ -49,7 +49,7 @@
 
 # include <boost_bind_bind.hpp>
 
-# include <math.h>
+# include <cmath>
 #endif
 
 #include "ViewProviderFemPostFunction.h"
diff --git a/src/Mod/Image/App/PreCompiled.h b/src/Mod/Image/App/PreCompiled.h
index 40dd25fef1..b7e7dd11e1 100644
--- a/src/Mod/Image/App/PreCompiled.h
+++ b/src/Mod/Image/App/PreCompiled.h
@@ -43,8 +43,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Image/Gui/PreCompiled.h b/src/Mod/Image/Gui/PreCompiled.h
index 0f9fea35c2..a315d43827 100644
--- a/src/Mod/Image/Gui/PreCompiled.h
+++ b/src/Mod/Image/Gui/PreCompiled.h
@@ -45,7 +45,7 @@
 #ifdef _PreComp_
 
 // standard
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 #include <iostream>
 #include <sstream>
diff --git a/src/Mod/Import/App/PreCompiled.h b/src/Mod/Import/App/PreCompiled.h
index 9e2cf88023..90d504886f 100644
--- a/src/Mod/Import/App/PreCompiled.h
+++ b/src/Mod/Import/App/PreCompiled.h
@@ -53,8 +53,8 @@
 #include <list>
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <io.h>
 #include <fcntl.h>
 #include <vector>
diff --git a/src/Mod/Import/Gui/PreCompiled.h b/src/Mod/Import/Gui/PreCompiled.h
index 7255b638e8..595e914fef 100644
--- a/src/Mod/Import/Gui/PreCompiled.h
+++ b/src/Mod/Import/Gui/PreCompiled.h
@@ -53,7 +53,7 @@
 // standard
 #include <list>
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 
 // STL
 #include <vector>
diff --git a/src/Mod/JtReader/App/PreCompiled.h b/src/Mod/JtReader/App/PreCompiled.h
index 7b5664a1ed..539b13b69a 100644
--- a/src/Mod/JtReader/App/PreCompiled.h
+++ b/src/Mod/JtReader/App/PreCompiled.h
@@ -31,8 +31,8 @@
 
 // standard
 
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
diff --git a/src/Mod/Measure/App/PreCompiled.h b/src/Mod/Measure/App/PreCompiled.h
index a8e89b685e..85a32d7fea 100644
--- a/src/Mod/Measure/App/PreCompiled.h
+++ b/src/Mod/Measure/App/PreCompiled.h
@@ -49,8 +49,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Mesh/App/PreCompiled.h b/src/Mod/Mesh/App/PreCompiled.h
index f83a8caed0..e7d96b7661 100644
--- a/src/Mod/Mesh/App/PreCompiled.h
+++ b/src/Mod/Mesh/App/PreCompiled.h
@@ -47,10 +47,10 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <cmath>
-#include <float.h>
+#include <cfloat>
 #include <fcntl.h>
 #include <ios>
 
diff --git a/src/Mod/Mesh/Gui/PreCompiled.h b/src/Mod/Mesh/Gui/PreCompiled.h
index 9fc7d4abd3..f68bbe7181 100644
--- a/src/Mod/Mesh/Gui/PreCompiled.h
+++ b/src/Mod/Mesh/Gui/PreCompiled.h
@@ -52,8 +52,8 @@
 #  include <gts.h>
 #endif
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
diff --git a/src/Mod/MeshPart/App/MeshFlatteningNurbs.cpp b/src/Mod/MeshPart/App/MeshFlatteningNurbs.cpp
index bf391c0430..6920c07693 100644
--- a/src/Mod/MeshPart/App/MeshFlatteningNurbs.cpp
+++ b/src/Mod/MeshPart/App/MeshFlatteningNurbs.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 #include "MeshFlatteningNurbs.h"
 #include <iostream>
-#include "math.h"
+#include <cmath>
 
 
 namespace nurbs{
diff --git a/src/Mod/MeshPart/App/PreCompiled.h b/src/Mod/MeshPart/App/PreCompiled.h
index 5dcb4dfac0..aa3bcdf414 100644
--- a/src/Mod/MeshPart/App/PreCompiled.h
+++ b/src/Mod/MeshPart/App/PreCompiled.h
@@ -49,8 +49,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/MeshPart/Gui/PreCompiled.h b/src/Mod/MeshPart/Gui/PreCompiled.h
index b5454e64f4..dc282198ee 100644
--- a/src/Mod/MeshPart/Gui/PreCompiled.h
+++ b/src/Mod/MeshPart/Gui/PreCompiled.h
@@ -53,7 +53,7 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL
diff --git a/src/Mod/Part/App/PreCompiled.h b/src/Mod/Part/App/PreCompiled.h
index bb9b1cb04f..db8239d08b 100644
--- a/src/Mod/Part/App/PreCompiled.h
+++ b/src/Mod/Part/App/PreCompiled.h
@@ -52,9 +52,9 @@
 #include <list>
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
+#include <cstdio>
 #include <fcntl.h>
-#include <assert.h>
+#include <cassert>
 
 #include <array>
 #include <vector>
diff --git a/src/Mod/Part/App/PropertyGeometryList.cpp b/src/Mod/Part/App/PropertyGeometryList.cpp
index 3061c3d60d..fbf36588b5 100644
--- a/src/Mod/Part/App/PropertyGeometryList.cpp
+++ b/src/Mod/Part/App/PropertyGeometryList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/Part/Gui/PreCompiled.h b/src/Mod/Part/Gui/PreCompiled.h
index dc7d2d08cc..3b2b7b46d7 100644
--- a/src/Mod/Part/Gui/PreCompiled.h
+++ b/src/Mod/Part/Gui/PreCompiled.h
@@ -57,12 +57,8 @@
 
 // standard
 #include <iostream>
-//#include <stdio.h>
 #include <cassert>
 #include <cfloat>
-//#include <io.h>
-//#include <fcntl.h>
-//#include <ctype.h>
 # include <cmath>
 #include <sstream>
 
diff --git a/src/Mod/Part/Gui/SoBrepEdgeSet.cpp b/src/Mod/Part/Gui/SoBrepEdgeSet.cpp
index a3a3a1c1e0..61ff3369ae 100644
--- a/src/Mod/Part/Gui/SoBrepEdgeSet.cpp
+++ b/src/Mod/Part/Gui/SoBrepEdgeSet.cpp
@@ -32,7 +32,7 @@
 # else
 #  include <GL/gl.h>
 # endif
-# include <float.h>
+# include <cfloat>
 # include <algorithm>
 # include <Inventor/SoPickedPoint.h>
 # include <Inventor/SoPrimitiveVertex.h>
diff --git a/src/Mod/Part/Gui/SoBrepFaceSet.cpp b/src/Mod/Part/Gui/SoBrepFaceSet.cpp
index 069846fdf6..4a93c115c4 100644
--- a/src/Mod/Part/Gui/SoBrepFaceSet.cpp
+++ b/src/Mod/Part/Gui/SoBrepFaceSet.cpp
@@ -29,7 +29,7 @@
 #endif
 
 #ifndef _PreComp_
-# include <float.h>
+# include <cfloat>
 # include <algorithm>
 # include <map>
 # include <Inventor/SoPickedPoint.h>
diff --git a/src/Mod/Part/Gui/SoBrepPointSet.cpp b/src/Mod/Part/Gui/SoBrepPointSet.cpp
index 7fd5ce5bcf..83db500521 100644
--- a/src/Mod/Part/Gui/SoBrepPointSet.cpp
+++ b/src/Mod/Part/Gui/SoBrepPointSet.cpp
@@ -32,7 +32,7 @@
 # else
 #  include <GL/gl.h>
 # endif
-# include <float.h>
+# include <cfloat>
 # include <algorithm>
 # include <Inventor/SoPickedPoint.h>
 # include <Inventor/SoPrimitiveVertex.h>
diff --git a/src/Mod/Part/Gui/SoFCShapeObject.cpp b/src/Mod/Part/Gui/SoFCShapeObject.cpp
index 2ea9155972..b50fa52274 100644
--- a/src/Mod/Part/Gui/SoFCShapeObject.cpp
+++ b/src/Mod/Part/Gui/SoFCShapeObject.cpp
@@ -32,7 +32,7 @@
 # else
 #  include <GL/gl.h>
 # endif
-# include <float.h>
+# include <cfloat>
 # include <algorithm>
 # include <Inventor/actions/SoCallbackAction.h>
 # include <Inventor/actions/SoGetBoundingBoxAction.h>
diff --git a/src/Mod/PartDesign/App/PreCompiled.h b/src/Mod/PartDesign/App/PreCompiled.h
index 4fb0457aa4..2a71ac9c90 100644
--- a/src/Mod/PartDesign/App/PreCompiled.h
+++ b/src/Mod/PartDesign/App/PreCompiled.h
@@ -49,8 +49,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
@@ -58,8 +58,7 @@
 #include <bitset>
 
 #include <cstring>
-
-# include <math.h>
+#include <cmath>
 
 // QT
 #include <QObject>
diff --git a/src/Mod/PartDesign/Gui/PreCompiled.h b/src/Mod/PartDesign/Gui/PreCompiled.h
index a9c3fcaf08..e9a637e132 100644
--- a/src/Mod/PartDesign/Gui/PreCompiled.h
+++ b/src/Mod/PartDesign/Gui/PreCompiled.h
@@ -52,7 +52,7 @@
 
 // standard
 #include <algorithm>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 #include <iostream>
 #include <sstream>
diff --git a/src/Mod/Path/App/PreCompiled.h b/src/Mod/Path/App/PreCompiled.h
index c65af103cf..6f297a259e 100644
--- a/src/Mod/Path/App/PreCompiled.h
+++ b/src/Mod/Path/App/PreCompiled.h
@@ -42,8 +42,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Path/Gui/PreCompiled.h b/src/Mod/Path/Gui/PreCompiled.h
index 0bb8a878ec..3a038a5f12 100644
--- a/src/Mod/Path/Gui/PreCompiled.h
+++ b/src/Mod/Path/Gui/PreCompiled.h
@@ -48,7 +48,7 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL
diff --git a/src/Mod/Points/App/PreCompiled.h b/src/Mod/Points/App/PreCompiled.h
index 94356f9bd5..0f089adbd6 100644
--- a/src/Mod/Points/App/PreCompiled.h
+++ b/src/Mod/Points/App/PreCompiled.h
@@ -43,8 +43,8 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
@@ -59,9 +59,9 @@
 #include <string>
 #include <vector>
 #include <bitset>
-#include <float.h>
+#include <cfloat>
 #include <cmath>
-#include <stdlib.h>
+#include <cstdlib>
 
 #endif //_PreComp_
 
diff --git a/src/Mod/Points/Gui/PreCompiled.h b/src/Mod/Points/Gui/PreCompiled.h
index d269663ba2..bf356ce52e 100644
--- a/src/Mod/Points/Gui/PreCompiled.h
+++ b/src/Mod/Points/Gui/PreCompiled.h
@@ -44,8 +44,8 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
diff --git a/src/Mod/Raytracing/App/PreCompiled.h b/src/Mod/Raytracing/App/PreCompiled.h
index 22435fbedc..eb516955c2 100644
--- a/src/Mod/Raytracing/App/PreCompiled.h
+++ b/src/Mod/Raytracing/App/PreCompiled.h
@@ -38,8 +38,8 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 
 // STL
diff --git a/src/Mod/Raytracing/Gui/PreCompiled.h b/src/Mod/Raytracing/Gui/PreCompiled.h
index 3d63359494..11722e9aad 100644
--- a/src/Mod/Raytracing/Gui/PreCompiled.h
+++ b/src/Mod/Raytracing/Gui/PreCompiled.h
@@ -43,8 +43,8 @@
 #ifdef _PreComp_
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
diff --git a/src/Mod/ReverseEngineering/App/PreCompiled.h b/src/Mod/ReverseEngineering/App/PreCompiled.h
index fb97580f11..101e5e8f22 100644
--- a/src/Mod/ReverseEngineering/App/PreCompiled.h
+++ b/src/Mod/ReverseEngineering/App/PreCompiled.h
@@ -57,8 +57,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/ReverseEngineering/Gui/PreCompiled.h b/src/Mod/ReverseEngineering/Gui/PreCompiled.h
index 0427c20501..25171dd7c0 100644
--- a/src/Mod/ReverseEngineering/Gui/PreCompiled.h
+++ b/src/Mod/ReverseEngineering/Gui/PreCompiled.h
@@ -50,7 +50,7 @@
 #ifdef _PreComp_
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL
diff --git a/src/Mod/Robot/App/PreCompiled.h b/src/Mod/Robot/App/PreCompiled.h
index a12d393de1..ae65dc14b3 100644
--- a/src/Mod/Robot/App/PreCompiled.h
+++ b/src/Mod/Robot/App/PreCompiled.h
@@ -41,8 +41,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/Robot/App/RobotAlgos.cpp b/src/Mod/Robot/App/RobotAlgos.cpp
index c784a544a8..21aea6cbb8 100644
--- a/src/Mod/Robot/App/RobotAlgos.cpp
+++ b/src/Mod/Robot/App/RobotAlgos.cpp
@@ -36,7 +36,7 @@
 #include "kdl_cp/chainjnttojacsolver.hpp"
 #include "kdl_cp/chainiksolverpos_nr.hpp"
 
-#include <stdio.h>
+#include <cstdio>
 #include <iostream>
 
 #include <Base/Console.h>
diff --git a/src/Mod/Robot/App/Simulation.cpp b/src/Mod/Robot/App/Simulation.cpp
index 362530688c..6445340982 100644
--- a/src/Mod/Robot/App/Simulation.cpp
+++ b/src/Mod/Robot/App/Simulation.cpp
@@ -30,7 +30,7 @@
 #include "kdl_cp/chain.hpp"
 #include "kdl_cp/frames_io.hpp"
 
-#include <stdio.h>
+#include <cstdio>
 #include <iostream>
 
 #include <Base/Console.h>
diff --git a/src/Mod/Robot/Gui/PreCompiled.h b/src/Mod/Robot/Gui/PreCompiled.h
index 7a31a032ed..942f351060 100644
--- a/src/Mod/Robot/Gui/PreCompiled.h
+++ b/src/Mod/Robot/Gui/PreCompiled.h
@@ -50,7 +50,7 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL
diff --git a/src/Mod/Sketcher/App/GeoList.cpp b/src/Mod/Sketcher/App/GeoList.cpp
index fc7139da39..e6d21e455e 100644
--- a/src/Mod/Sketcher/App/GeoList.cpp
+++ b/src/Mod/Sketcher/App/GeoList.cpp
@@ -27,7 +27,7 @@
 
 #endif  // #ifndef _PreComp_
 
-#include <assert.h>
+#include <cassert>
 
 #include <Base/Vector3D.h>
 #include <Base/Exception.h>
diff --git a/src/Mod/Sketcher/App/PreCompiled.h b/src/Mod/Sketcher/App/PreCompiled.h
index f8af11c7ec..c84da9bff5 100644
--- a/src/Mod/Sketcher/App/PreCompiled.h
+++ b/src/Mod/Sketcher/App/PreCompiled.h
@@ -44,8 +44,8 @@
 // standard
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <memory>
diff --git a/src/Mod/Sketcher/App/PropertyConstraintList.cpp b/src/Mod/Sketcher/App/PropertyConstraintList.cpp
index 879074d532..19a9d80863 100644
--- a/src/Mod/Sketcher/App/PropertyConstraintList.cpp
+++ b/src/Mod/Sketcher/App/PropertyConstraintList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp b/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
index f583f8048e..8a77da3030 100644
--- a/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
+++ b/src/Mod/Sketcher/Gui/CommandCreateGeo.cpp
@@ -29,7 +29,7 @@
 # include <QInputDialog>
 # include <QMessageBox>
 # include <QString>
-# include <stdlib.h>
+# include <cstdlib>
 # include <qdebug.h>
 # include <GC_MakeEllipse.hxx>
 # include <boost/math/special_functions/fpclassify.hpp>
diff --git a/src/Mod/Sketcher/Gui/PreCompiled.h b/src/Mod/Sketcher/Gui/PreCompiled.h
index bd7d1cdd11..b923ef4298 100644
--- a/src/Mod/Sketcher/Gui/PreCompiled.h
+++ b/src/Mod/Sketcher/Gui/PreCompiled.h
@@ -52,7 +52,7 @@
 #include <cassert>
 #include <cmath>
 
-#include <stdlib.h>
+#include <cstdlib>
 
 // STL
 #include <vector>
diff --git a/src/Mod/Spreadsheet/App/PreCompiled.h b/src/Mod/Spreadsheet/App/PreCompiled.h
index 98e78b7695..5d7f1e8416 100644
--- a/src/Mod/Spreadsheet/App/PreCompiled.h
+++ b/src/Mod/Spreadsheet/App/PreCompiled.h
@@ -47,8 +47,8 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
-#include <math.h>
+#include <cassert>
+#include <cmath>
 
 // STL
 #include <vector>
diff --git a/src/Mod/Spreadsheet/App/Utils.cpp b/src/Mod/Spreadsheet/App/Utils.cpp
index 31f8a9fdfe..f651c9e61f 100644
--- a/src/Mod/Spreadsheet/App/Utils.cpp
+++ b/src/Mod/Spreadsheet/App/Utils.cpp
@@ -27,7 +27,7 @@
 
 #include "Utils.h"
 #include <sstream>
-#include <stdlib.h>
+#include <cstdlib>
 #include <boost/regex.hpp>
 #include <Base/Exception.h>
 #include "Sheet.h"
diff --git a/src/Mod/Spreadsheet/Gui/Command.cpp b/src/Mod/Spreadsheet/Gui/Command.cpp
index 5e141262e9..48f96e5d90 100644
--- a/src/Mod/Spreadsheet/Gui/Command.cpp
+++ b/src/Mod/Spreadsheet/Gui/Command.cpp
@@ -29,7 +29,7 @@
 # include <QTextStream>
 #endif
 
-#include <time.h>
+#include <ctime>
 #if defined(FC_OS_WIN32)
 #include <sys/timeb.h>
 #endif
diff --git a/src/Mod/Spreadsheet/Gui/PreCompiled.h b/src/Mod/Spreadsheet/Gui/PreCompiled.h
index 16385b9d19..004e0b7d83 100644
--- a/src/Mod/Spreadsheet/Gui/PreCompiled.h
+++ b/src/Mod/Spreadsheet/Gui/PreCompiled.h
@@ -49,8 +49,8 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
-#include <math.h>
+#include <cassert>
+#include <cmath>
 
 // STL
 #include <vector>
diff --git a/src/Mod/Spreadsheet/Gui/qtcolorpicker.cpp b/src/Mod/Spreadsheet/Gui/qtcolorpicker.cpp
index 5bf2485ee0..2ec41dba04 100644
--- a/src/Mod/Spreadsheet/Gui/qtcolorpicker.cpp
+++ b/src/Mod/Spreadsheet/Gui/qtcolorpicker.cpp
@@ -62,7 +62,7 @@
 #include <QtGui/QKeyEvent>
 #include <QtGui/QShowEvent>
 #include <QtGui/QMouseEvent>
-#include <math.h>
+#include <cmath>
 
 #include <QScreen>
 #include <Gui/FileDialog.h>
diff --git a/src/Mod/Start/Gui/PreCompiled.h b/src/Mod/Start/Gui/PreCompiled.h
index ae62f427ea..65d231db2f 100644
--- a/src/Mod/Start/Gui/PreCompiled.h
+++ b/src/Mod/Start/Gui/PreCompiled.h
@@ -37,7 +37,7 @@
 #ifdef _PreComp_
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL
diff --git a/src/Mod/TechDraw/App/DrawDimHelper.cpp b/src/Mod/TechDraw/App/DrawDimHelper.cpp
index 1fcb751a82..e529922ac0 100644
--- a/src/Mod/TechDraw/App/DrawDimHelper.cpp
+++ b/src/Mod/TechDraw/App/DrawDimHelper.cpp
@@ -27,7 +27,7 @@
 # include <cstring>
 # include <cstdlib>
 #include <cmath>
-#include <float.h>
+#include <cfloat>
 #include <string>
 # include <exception>
 
diff --git a/src/Mod/TechDraw/App/PreCompiled.h b/src/Mod/TechDraw/App/PreCompiled.h
index 40aaae011a..8a1847fd2e 100644
--- a/src/Mod/TechDraw/App/PreCompiled.h
+++ b/src/Mod/TechDraw/App/PreCompiled.h
@@ -51,8 +51,8 @@
 #include <fstream>
 #include <iostream>
 #include <sstream>
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 #include <string>
 #include <map>
 #include <vector>
diff --git a/src/Mod/TechDraw/App/PropertyCenterLineList.cpp b/src/Mod/TechDraw/App/PropertyCenterLineList.cpp
index 1439ebb718..adf48d8fa0 100644
--- a/src/Mod/TechDraw/App/PropertyCenterLineList.cpp
+++ b/src/Mod/TechDraw/App/PropertyCenterLineList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/TechDraw/App/PropertyCosmeticEdgeList.cpp b/src/Mod/TechDraw/App/PropertyCosmeticEdgeList.cpp
index 297597c3d1..2356fbe2ff 100644
--- a/src/Mod/TechDraw/App/PropertyCosmeticEdgeList.cpp
+++ b/src/Mod/TechDraw/App/PropertyCosmeticEdgeList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/TechDraw/App/PropertyCosmeticVertexList.cpp b/src/Mod/TechDraw/App/PropertyCosmeticVertexList.cpp
index 21176b2ad3..094dcecb71 100644
--- a/src/Mod/TechDraw/App/PropertyCosmeticVertexList.cpp
+++ b/src/Mod/TechDraw/App/PropertyCosmeticVertexList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/TechDraw/App/PropertyGeomFormatList.cpp b/src/Mod/TechDraw/App/PropertyGeomFormatList.cpp
index 7ffdc01467..6bb4e7f18a 100644
--- a/src/Mod/TechDraw/App/PropertyGeomFormatList.cpp
+++ b/src/Mod/TechDraw/App/PropertyGeomFormatList.cpp
@@ -24,7 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-#   include <assert.h>
+#   include <cassert>
 #endif
 
 /// Here the FreeCAD includes sorted by Base,App,Gui......
diff --git a/src/Mod/TechDraw/Gui/MDIViewPage.cpp b/src/Mod/TechDraw/Gui/MDIViewPage.cpp
index 91650afb84..e5199baab4 100644
--- a/src/Mod/TechDraw/Gui/MDIViewPage.cpp
+++ b/src/Mod/TechDraw/Gui/MDIViewPage.cpp
@@ -44,7 +44,7 @@
 
 #endif  // #ifndef _PreComp_
 
-#include <math.h>
+#include <cmath>
 
 #include "MDIViewPage.h"
 
diff --git a/src/Mod/TechDraw/Gui/QGCustomBorder.cpp b/src/Mod/TechDraw/Gui/QGCustomBorder.cpp
index 5b08912ba3..c6f5901537 100644
--- a/src/Mod/TechDraw/Gui/QGCustomBorder.cpp
+++ b/src/Mod/TechDraw/Gui/QGCustomBorder.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGCustomClip.cpp b/src/Mod/TechDraw/Gui/QGCustomClip.cpp
index bb3ffb7932..44e6c441cd 100644
--- a/src/Mod/TechDraw/Gui/QGCustomClip.cpp
+++ b/src/Mod/TechDraw/Gui/QGCustomClip.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGCustomLabel.cpp b/src/Mod/TechDraw/Gui/QGCustomLabel.cpp
index 50024743fc..2ea0037485 100644
--- a/src/Mod/TechDraw/Gui/QGCustomLabel.cpp
+++ b/src/Mod/TechDraw/Gui/QGCustomLabel.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGCustomRect.cpp b/src/Mod/TechDraw/Gui/QGCustomRect.cpp
index 036ff64479..cf82c90f56 100644
--- a/src/Mod/TechDraw/Gui/QGCustomRect.cpp
+++ b/src/Mod/TechDraw/Gui/QGCustomRect.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGCustomText.cpp b/src/Mod/TechDraw/Gui/QGCustomText.cpp
index 8827134251..3a8ac04327 100644
--- a/src/Mod/TechDraw/Gui/QGCustomText.cpp
+++ b/src/Mod/TechDraw/Gui/QGCustomText.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGDisplayArea.cpp b/src/Mod/TechDraw/Gui/QGDisplayArea.cpp
index 45a9336748..0afaf632b5 100644
--- a/src/Mod/TechDraw/Gui/QGDisplayArea.cpp
+++ b/src/Mod/TechDraw/Gui/QGDisplayArea.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIArrow.cpp b/src/Mod/TechDraw/Gui/QGIArrow.cpp
index 88dbadd72b..0ff68991cc 100644
--- a/src/Mod/TechDraw/Gui/QGIArrow.cpp
+++ b/src/Mod/TechDraw/Gui/QGIArrow.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QMenu>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGICMark.cpp b/src/Mod/TechDraw/Gui/QGICMark.cpp
index 31a6cb6ce2..f061791920 100644
--- a/src/Mod/TechDraw/Gui/QGICMark.cpp
+++ b/src/Mod/TechDraw/Gui/QGICMark.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGICaption.cpp b/src/Mod/TechDraw/Gui/QGICaption.cpp
index 6b722e5ef3..c4dbbe40eb 100644
--- a/src/Mod/TechDraw/Gui/QGICaption.cpp
+++ b/src/Mod/TechDraw/Gui/QGICaption.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIDecoration.cpp b/src/Mod/TechDraw/Gui/QGIDecoration.cpp
index dcea41af80..7c7c2156ac 100644
--- a/src/Mod/TechDraw/Gui/QGIDecoration.cpp
+++ b/src/Mod/TechDraw/Gui/QGIDecoration.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 //#include <QGraphicsScene>
 //#include <QGraphicsSceneHoverEvent>
 //#include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIDimLines.cpp b/src/Mod/TechDraw/Gui/QGIDimLines.cpp
index babbfa204f..6d8a09a8bb 100644
--- a/src/Mod/TechDraw/Gui/QGIDimLines.cpp
+++ b/src/Mod/TechDraw/Gui/QGIDimLines.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QMenu>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIEdge.cpp b/src/Mod/TechDraw/Gui/QGIEdge.cpp
index 8953cd40ca..380e4b762a 100644
--- a/src/Mod/TechDraw/Gui/QGIEdge.cpp
+++ b/src/Mod/TechDraw/Gui/QGIEdge.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QMouseEvent>
 #include <QPainter>
diff --git a/src/Mod/TechDraw/Gui/QGILeaderLine.cpp b/src/Mod/TechDraw/Gui/QGILeaderLine.cpp
index f357decca8..58adadc082 100644
--- a/src/Mod/TechDraw/Gui/QGILeaderLine.cpp
+++ b/src/Mod/TechDraw/Gui/QGILeaderLine.cpp
@@ -37,7 +37,7 @@
 #include <QPaintDevice>
 #include <QSvgGenerator>
 #include <QVector2D>
-#include <math.h>
+#include <cmath>
 #endif
 
 #include <App/Application.h>
diff --git a/src/Mod/TechDraw/Gui/QGIMatting.cpp b/src/Mod/TechDraw/Gui/QGIMatting.cpp
index b4c902be74..72bcdc164a 100644
--- a/src/Mod/TechDraw/Gui/QGIMatting.cpp
+++ b/src/Mod/TechDraw/Gui/QGIMatting.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QPainter>
 #include <QPainterPath>
 #include <QStyleOptionGraphicsItem>
diff --git a/src/Mod/TechDraw/Gui/QGIPrimPath.cpp b/src/Mod/TechDraw/Gui/QGIPrimPath.cpp
index 59933a6a93..93e7b91300 100644
--- a/src/Mod/TechDraw/Gui/QGIPrimPath.cpp
+++ b/src/Mod/TechDraw/Gui/QGIPrimPath.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIRichAnno.cpp b/src/Mod/TechDraw/Gui/QGIRichAnno.cpp
index eddfc2f04a..9d9b9a9dde 100644
--- a/src/Mod/TechDraw/Gui/QGIRichAnno.cpp
+++ b/src/Mod/TechDraw/Gui/QGIRichAnno.cpp
@@ -46,7 +46,7 @@
 #include <QDialog>
 
 
-# include <math.h>
+# include <cmath>
 #endif
 
 #include <App/Application.h>
diff --git a/src/Mod/TechDraw/Gui/QGIVertex.cpp b/src/Mod/TechDraw/Gui/QGIVertex.cpp
index c800234a45..6c89d52468 100644
--- a/src/Mod/TechDraw/Gui/QGIVertex.cpp
+++ b/src/Mod/TechDraw/Gui/QGIVertex.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsSceneHoverEvent>
 #include <QMouseEvent>
diff --git a/src/Mod/TechDraw/Gui/QGIWeldSymbol.cpp b/src/Mod/TechDraw/Gui/QGIWeldSymbol.cpp
index 9c58e78065..f1a3ec0cee 100644
--- a/src/Mod/TechDraw/Gui/QGIWeldSymbol.cpp
+++ b/src/Mod/TechDraw/Gui/QGIWeldSymbol.cpp
@@ -36,7 +36,7 @@
   # include <QPaintDevice>
   # include <QSvgGenerator>
 
-  # include <math.h>
+  # include <cmath>
 #endif
 
 #include <App/Application.h>
diff --git a/src/Mod/TechDraw/Gui/QGTracker.cpp b/src/Mod/TechDraw/Gui/QGTracker.cpp
index fd1f65862e..de45e5b523 100644
--- a/src/Mod/TechDraw/Gui/QGTracker.cpp
+++ b/src/Mod/TechDraw/Gui/QGTracker.cpp
@@ -22,7 +22,7 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <assert.h>
+#include <cassert>
 #include <QGraphicsScene>
 #include <QGraphicsView>
 #include <QGraphicsSceneHoverEvent>
diff --git a/src/Mod/TechDraw/Gui/mtextedit.cpp b/src/Mod/TechDraw/Gui/mtextedit.cpp
index 224a37c67a..fe7ef3ef86 100644
--- a/src/Mod/TechDraw/Gui/mtextedit.cpp
+++ b/src/Mod/TechDraw/Gui/mtextedit.cpp
@@ -27,7 +27,7 @@
 #include <QImage>
 #include <QByteArray>
 #include <QBuffer>
-#include <stdlib.h>
+#include <cstdlib>
 
 
 MTextEdit::MTextEdit(QWidget *parent) : QTextEdit(parent) {
diff --git a/src/Mod/Test/Gui/PreCompiled.h b/src/Mod/Test/Gui/PreCompiled.h
index 37c33649b9..fad02fbffb 100644
--- a/src/Mod/Test/Gui/PreCompiled.h
+++ b/src/Mod/Test/Gui/PreCompiled.h
@@ -43,8 +43,8 @@
 #endif
 
 // standard
-#include <stdio.h>
-#include <assert.h>
+#include <cstdio>
+#include <cassert>
 
 // STL
 #include <algorithm>
diff --git a/src/Mod/Web/Gui/PreCompiled.h b/src/Mod/Web/Gui/PreCompiled.h
index 7d45cbc756..b1e7c9585e 100644
--- a/src/Mod/Web/Gui/PreCompiled.h
+++ b/src/Mod/Web/Gui/PreCompiled.h
@@ -38,7 +38,7 @@
 
 // standard
 #include <iostream>
-#include <assert.h>
+#include <cassert>
 #include <cmath>
 
 // STL