diff --git a/include/osgGLUT/Viewer b/include/osgGLUT/Viewer
index 023841e4f..fccccdd68 100644
--- a/include/osgGLUT/Viewer
+++ b/include/osgGLUT/Viewer
@@ -40,15 +40,15 @@ class OSGGLUT_EXPORT Viewer : public Window, public osgGA::GUIActionAdapter
           * only available for backwards compatibility.*/
         virtual void init(osg::Node* rootnode);
 
-        virtual void addViewport(osgUtil::SceneView* sv,
+        virtual unsigned int addViewport(osgUtil::SceneView* sv,
                                  float x     = 0.0, float y      = 0.0,        
                                  float width = 1.0, float height = 1.0);
 
-        virtual void addViewport(osg::Node*,
+        virtual unsigned int addViewport(osg::Node*,
                                  float x     = 0.0, float y      = 0.0,        
                                  float width = 1.0, float height = 1.0);
 
-        const int getNumViewports() const { return _viewportList.size(); }
+        const unsigned int getNumViewports() const { return _viewportList.size(); }
 
         osgUtil::SceneView* getViewportSceneView(unsigned int pos) 
             { return _viewportList[pos].sceneView.get(); }
diff --git a/src/osgGLUT/Viewer.cpp b/src/osgGLUT/Viewer.cpp
index e140fd4ac..5bc5c383a 100644
--- a/src/osgGLUT/Viewer.cpp
+++ b/src/osgGLUT/Viewer.cpp
@@ -667,7 +667,7 @@ void Viewer::display()
     // draw traverasal.
     times[2].timeDraw=0.0f;
     
-    for(int i = 0; i < getNumViewports(); i++ )
+    for(unsigned int i = 0; i < getNumViewports(); i++ )
     {
         // application traverasal.
         times[2].timeApp+=app(i);
@@ -1388,7 +1388,7 @@ bool Viewer::run()
 }
 
 
-void Viewer::addViewport(osgUtil::SceneView* sv,
+unsigned int Viewer::addViewport(osgUtil::SceneView* sv,
                          float x, float y, float width, float height) 
 { 
     ViewportDef def;
@@ -1397,21 +1397,25 @@ void Viewer::addViewport(osgUtil::SceneView* sv,
     def.viewport[1] = y;
     def.viewport[2] = width;
     def.viewport[3] = height;
+    
+    unsigned int pos = _viewportList.size();
     _viewportList.push_back(def);
+    
+    return pos;
 }
 
 
 /**
   * Adds a default SceneView referring to the passed scene graph root.
   */
-void Viewer::addViewport(osg::Node* rootnode,
+unsigned int Viewer::addViewport(osg::Node* rootnode,
                          float x, float y, float width, float height) 
 {
     osgUtil::SceneView *sceneView = osgNew osgUtil::SceneView(_displaySettings.get());
     sceneView->setDefaults();
     sceneView->setSceneData(rootnode);
 
-    addViewport( sceneView, x, y, width, height );
+    return addViewport( sceneView, x, y, width, height );
 }
 
 void Viewer::init(osg::Node* rootnode)