diff --git a/src/osgViewer/Viewer.cpp b/src/osgViewer/Viewer.cpp
index 1c612d823..ec4dbe093 100644
--- a/src/osgViewer/Viewer.cpp
+++ b/src/osgViewer/Viewer.cpp
@@ -798,6 +798,18 @@ void Viewer::eventTraversal()
         }
     }
 
+    // pass on the coorindates of the main camera to make sure the frame event is scaled appropriately.
+    if (getCamera()->getViewport())
+    {
+        osg::Viewport* viewport = getCamera()->getViewport();
+        eventState->setInputRange( viewport->x(), viewport->y(), viewport->x() + viewport->width(), viewport->y() + viewport->height());
+    }
+    else
+    {
+        eventState->setInputRange(-1.0, -1.0, 1.0, 1.0);
+    }
+
+    // create a frame event for the new frame.
     _eventQueue->frame( getFrameStamp()->getReferenceTime() );
 
     // OSG_NOTICE<<"mouseEventState Xmin = "<<eventState->getXmin()<<" Ymin="<<eventState->getYmin()<<" xMax="<<eventState->getXmax()<<" Ymax="<<eventState->getYmax()<<std::endl;