diff --git a/src/osgPlugins/Inventor/ConvertFromInventor.cpp b/src/osgPlugins/Inventor/ConvertFromInventor.cpp
index 547801694..444ce24a7 100644
--- a/src/osgPlugins/Inventor/ConvertFromInventor.cpp
+++ b/src/osgPlugins/Inventor/ConvertFromInventor.cpp
@@ -402,7 +402,7 @@ ConvertFromInventor::preLight(void* data, SoCallbackAction* action,
         SoSpotLight* spotLight = (SoSpotLight *) node;
 
         osgLight->setSpotExponent(spotLight->dropOffRate.getValue() * 128.0);
-        osgLight->setSpotCutoff(spotLight->cutOffAngle.getValue()*180.0/M_PI);
+        osgLight->setSpotCutoff(spotLight->cutOffAngle.getValue()*180.0/osg::PI);
 
         osg::Vec3 transVec;
         thisPtr->transformLight(action, spotLight->location.getValue(), transVec);
@@ -764,7 +764,7 @@ ConvertFromInventor::preRotor(void* data, SoCallbackAction *,
     osg::Vec3 axis(ivAxis[0], ivAxis[1], ivAxis[2]);
     osgUtil::TransformCallback* rotorCallback 
         = new osgUtil::TransformCallback(pivot, axis, 
-                                         2 * M_PI * ivRotor->speed.getValue());
+                                         2 * osg::PI * ivRotor->speed.getValue());
 
     // Set the app callback
     rotorTransform->setUpdateCallback(rotorCallback);
diff --git a/src/osgPlugins/Inventor/PendulumCallback.cpp b/src/osgPlugins/Inventor/PendulumCallback.cpp
index c637ce6f9..0b3e6d493 100644
--- a/src/osgPlugins/Inventor/PendulumCallback.cpp
+++ b/src/osgPlugins/Inventor/PendulumCallback.cpp
@@ -35,10 +35,10 @@ void PendulumCallback::operator() (osg::Node* node, osg::NodeVisitor* nv)
     if (nv->getTraversalNumber()!=_previousTraversalNumber)
     {
         double currentTime = fs->getReferenceTime();
-        _angle += (currentTime - _previousTime) * 2 * M_PI * _frequency;
+        _angle += (currentTime - _previousTime) * 2 * osg::PI * _frequency;
         
         double frac = 0.5 + 0.5 * sin(_angle);
-        double rotAngle = _endAngle  - _startAngle - M_PI 
+        double rotAngle = _endAngle  - _startAngle - osg::PI 
                 + (1.0 - frac) * _startAngle + frac * _endAngle;
 
         // update the specified transform
diff --git a/src/osgPlugins/Inventor/ShuttleCallback.cpp b/src/osgPlugins/Inventor/ShuttleCallback.cpp
index 0dc4a4eb1..3e8564841 100644
--- a/src/osgPlugins/Inventor/ShuttleCallback.cpp
+++ b/src/osgPlugins/Inventor/ShuttleCallback.cpp
@@ -34,7 +34,7 @@ void ShuttleCallback::operator() (osg::Node* node, osg::NodeVisitor* nv)
     if (nv->getTraversalNumber()!=_previousTraversalNumber)
     {
         double currentTime = fs->getReferenceTime();
-        _angle += (currentTime - _previousTime) * 2 * M_PI * _frequency;
+        _angle += (currentTime - _previousTime) * 2 * osg::PI * _frequency;
         
         double frac = 0.5 + 0.5 * sin(_angle);