diff --git a/include/osgUtil/IntersectionVisitor b/include/osgUtil/IntersectionVisitor
index de8029bba..638739caf 100644
--- a/include/osgUtil/IntersectionVisitor
+++ b/include/osgUtil/IntersectionVisitor
@@ -162,18 +162,22 @@ class OSGUTIL_EXPORT IntersectionVisitor : public osg::NodeVisitor
         void pushWindowMatrix(osg::Viewport* viewport) { _windowStack.push_back(new osg::RefMatrix( viewport->computeWindowMatrix()) ); }
         void popWindowMatrix() { _windowStack.pop_back(); }
         osg::RefMatrix* getWindowMatrix() { return _windowStack.empty() ? 0 :  _windowStack.back().get(); }
+        const osg::RefMatrix* getWindowMatrix() const { return _windowStack.empty() ? 0 :  _windowStack.back().get(); }
 
         void pushProjectionMatrix(osg::RefMatrix* matrix) { _projectionStack.push_back(matrix); }
         void popProjectionMatrix() { _projectionStack.pop_back(); }
         osg::RefMatrix* getProjectionMatrix() { return _projectionStack.empty() ? 0 :  _projectionStack.back().get(); }
+        const osg::RefMatrix* getProjectionMatrix() const { return _projectionStack.empty() ? 0 :  _projectionStack.back().get(); }
 
         void pushViewMatrix(osg::RefMatrix* matrix) { _viewStack.push_back(matrix); }
         void popViewMatrix() { _viewStack.pop_back(); }
         osg::RefMatrix* getViewMatrix() { return _viewStack.empty() ? 0 :  _viewStack.back().get(); }
+        const osg::RefMatrix* getViewMatrix() const { return _viewStack.empty() ? 0 :  _viewStack.back().get(); }
 
         void pushModelMatrix(osg::RefMatrix* matrix) { _modelStack.push_back(matrix); }
         void popModelMatrix() { _modelStack.pop_back(); } 
         osg::RefMatrix* getModelMatrix() { return _modelStack.empty() ? 0 :  _modelStack.back().get(); }
+        const osg::RefMatrix* getModelMatrix() const { return _modelStack.empty() ? 0 :  _modelStack.back().get(); }
 
     public: