diff --git a/src/Gui/ViewProviderOriginFeature.cpp b/src/Gui/ViewProviderOriginFeature.cpp
index 783ba6e9d..345e77da9 100644
--- a/src/Gui/ViewProviderOriginFeature.cpp
+++ b/src/Gui/ViewProviderOriginFeature.cpp
@@ -54,7 +54,7 @@ ViewProviderOriginFeature::ViewProviderOriginFeature () {
     ADD_PROPERTY_TYPE ( Size, (ViewProviderOrigin::defaultSize()), 0, App::Prop_ReadOnly,
             "Visual size of the feature" );
 
-    ShapeColor.setValue ( 50./255, 150./255, 250./255 ); // Set default color for origin (light-blue)
+    ShapeColor.setValue ( 50.f/255, 150.f/255, 250.f/255 ); // Set default color for origin (light-blue)
     BoundingBox.setStatus(App::Property::Hidden, true); // Hide Boundingbox from the user due to it doesn't make sence
 
     // Create node for scaling the origin
diff --git a/src/Mod/Fem/App/FemConstraint.cpp b/src/Mod/Fem/App/FemConstraint.cpp
index 298f86488..8424fc979 100644
--- a/src/Mod/Fem/App/FemConstraint.cpp
+++ b/src/Mod/Fem/App/FemConstraint.cpp
@@ -62,9 +62,11 @@
 using namespace Fem;
 
 // maybe in the c++ standard later, older compiler don't have round()
+#if _MSC_VER <= 1700
 double round(double r) {
     return (r > 0.0) ? floor(r + 0.5) : ceil(r - 0.5);
 }
+#endif
 
 PROPERTY_SOURCE(Fem::Constraint, App::DocumentObject);
 
diff --git a/src/Mod/Mesh/Gui/PreCompiled.h b/src/Mod/Mesh/Gui/PreCompiled.h
index 9887c1888..3ffe1f2d5 100644
--- a/src/Mod/Mesh/Gui/PreCompiled.h
+++ b/src/Mod/Mesh/Gui/PreCompiled.h
@@ -41,6 +41,7 @@
 #   pragma warning( disable : 4251 )
 #   pragma warning( disable : 4503 )
 #   pragma warning( disable : 4275 )
+#   pragma warning( disable : 4273 )
 #   pragma warning( disable : 4786 )  // specifier longer then 255 chars
 #endif
 
diff --git a/src/Mod/Part/Gui/PreCompiled.h b/src/Mod/Part/Gui/PreCompiled.h
index 0e6285e70..f6a9a1782 100644
--- a/src/Mod/Part/Gui/PreCompiled.h
+++ b/src/Mod/Part/Gui/PreCompiled.h
@@ -39,15 +39,16 @@
 # define NOMINMAX
 #endif
 
-
-#ifdef _PreComp_
 // here get the warnings of too long specifiers disabled (needed for VC6)
 #ifdef _MSC_VER
 # pragma warning( disable : 4251 )
 # pragma warning( disable : 4503 )
 # pragma warning( disable : 4786 )  // specifier longer then 255 chars
+# pragma warning( disable : 4273 )
 #endif
 
+#ifdef _PreComp_
+
 // standard
 #include <iostream>
 //#include <stdio.h>
diff --git a/src/Mod/PartDesign/Gui/ViewProviderAddSub.cpp b/src/Mod/PartDesign/Gui/ViewProviderAddSub.cpp
index 282bf9ade..64f40a027 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderAddSub.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderAddSub.cpp
@@ -88,7 +88,7 @@ void ViewProviderAddSub::attach(App::DocumentObject* obj) {
     else
         material->diffuseColor = SbColor(1,0,0);
     
-    material->transparency = 0.7;    
+    material->transparency = 0.7f;
     auto* pick = new SoPickStyle();
     pick->style = SoPickStyle::UNPICKABLE;
     
diff --git a/src/Mod/PartDesign/Gui/ViewProviderDatumCS.cpp b/src/Mod/PartDesign/Gui/ViewProviderDatumCS.cpp
index 594c6803c..489777628 100644
--- a/src/Mod/PartDesign/Gui/ViewProviderDatumCS.cpp
+++ b/src/Mod/PartDesign/Gui/ViewProviderDatumCS.cpp
@@ -129,7 +129,7 @@ void ViewProviderDatumCoordinateSystem::attach ( App::DocumentObject *obj ) {
 
     getShapeRoot ()->addChild(axisLabelYToZTrans);
     SoRotation *rot = new SoRotation();
-    rot->rotation = SbRotation(SbVec3f(1,1,1), 2*M_PI/3);
+    rot->rotation = SbRotation(SbVec3f(1,1,1), static_cast<float>(2*M_PI/3));
     getShapeRoot ()->addChild(rot);
     t = new SoAsciiText();
     t->string = "Z";
diff --git a/src/Mod/Robot/Gui/PreCompiled.h b/src/Mod/Robot/Gui/PreCompiled.h
index 9b963bc27..629d92698 100644
--- a/src/Mod/Robot/Gui/PreCompiled.h
+++ b/src/Mod/Robot/Gui/PreCompiled.h
@@ -43,6 +43,7 @@
 
 #ifdef _MSC_VER
 #   pragma warning(disable : 4005)
+#   pragma warning(disable : 4273)
 #endif
 
 #ifdef _PreComp_