diff --git a/include/osgViewer/Renderer b/include/osgViewer/Renderer
index efea691ed..2cf847a15 100644
--- a/include/osgViewer/Renderer
+++ b/include/osgViewer/Renderer
@@ -98,6 +98,8 @@ class OSGVIEWER_EXPORT Renderer : public osg::GraphicsOperation, public OpenGLQu
             typedef std::list<osgUtil::SceneView*> SceneViewList;
             SceneViewList _queue;
             
+            TheadSafeQueue();
+            
             void release()
             {
                 _block.release();
diff --git a/src/osgViewer/Renderer.cpp b/src/osgViewer/Renderer.cpp
index 327c3fc1a..88fd65f51 100644
--- a/src/osgViewer/Renderer.cpp
+++ b/src/osgViewer/Renderer.cpp
@@ -121,6 +121,11 @@ void OpenGLQuerySupport::initialize(osg::State* state)
 //
 //  TheadSafeQueue
 
+Renderer::TheadSafeQueue::TheadSafeQueue()
+{
+    _block.set(false);
+}
+
 osgUtil::SceneView* Renderer::TheadSafeQueue::takeFront()
 {
     if (_queue.empty()) _block.block();