diff --git a/include/osgParticle/ParticleSystem b/include/osgParticle/ParticleSystem
index 67f3ffb4e..dd49ea5a3 100644
--- a/include/osgParticle/ParticleSystem
+++ b/include/osgParticle/ParticleSystem
@@ -166,7 +166,7 @@ namespace osgParticle
 
         virtual osg::BoundingBox computeBound() const;
         
-        osgDB::ReadWriteMutex& getReadWriteMutex() const { return _readWriteMutex; }
+        osgDB::ReadWriteMutex* getReadWriteMutex() const { return &_readWriteMutex; }
 
     protected:
 
diff --git a/src/osgParticle/ConnectedParticleSystem.cpp b/src/osgParticle/ConnectedParticleSystem.cpp
index 1138e830f..120ea3149 100644
--- a/src/osgParticle/ConnectedParticleSystem.cpp
+++ b/src/osgParticle/ConnectedParticleSystem.cpp
@@ -114,9 +114,12 @@ void ConnectedParticleSystem::reuseParticle(int particleIndex)
 
 void ConnectedParticleSystem::drawImplementation(osg::State& state) const
 {
+    osgDB::ScopedReadLock lock(_readWriteMutex);
+
     const Particle* particle = (_startParticle != Particle::INVALID_INDEX) ? &_particles[_startParticle] : 0;
     if (!particle) return;
     
+
     osg::Vec4 pixelSizeVector = osg::CullingSet::computePixelSizeVector(*state.getCurrentViewport(),state.getProjectionMatrix(),state.getModelViewMatrix());
     float unitPixelSize = fabs(1.0/(particle->getPosition()*pixelSizeVector));
     float pixelSizeOfFirstParticle = unitPixelSize * particle->getCurrentSize();
diff --git a/src/osgParticle/ParticleProcessor.cpp b/src/osgParticle/ParticleProcessor.cpp
index bf72416b8..58bf00c5f 100644
--- a/src/osgParticle/ParticleProcessor.cpp
+++ b/src/osgParticle/ParticleProcessor.cpp
@@ -64,7 +64,7 @@ void osgParticle::ParticleProcessor::traverse(osg::NodeVisitor& nv)
         {
             if (nv.getFrameStamp())
             {
-                osgDB::ScopedWriteLock lock(_ps->getReadWriteMutex());
+                osgDB::ScopedWriteLock lock(*(_ps->getReadWriteMutex()));
 
                 //added- 1/17/06- bgandere@nps.edu 
                 //a check to make sure we havent updated yet this frame
diff --git a/src/osgParticle/ParticleSystemUpdater.cpp b/src/osgParticle/ParticleSystemUpdater.cpp
index 2266fca42..02c1ef5cb 100644
--- a/src/osgParticle/ParticleSystemUpdater.cpp
+++ b/src/osgParticle/ParticleSystemUpdater.cpp
@@ -40,7 +40,7 @@ void osgParticle::ParticleSystemUpdater::traverse(osg::NodeVisitor& nv)
                     {
                         ParticleSystem* ps = i->get();
                         
-                        osgDB::ScopedWriteLock lock(ps->getReadWriteMutex());
+                        osgDB::ScopedWriteLock lock(*(ps->getReadWriteMutex()));
 
                         if (!ps->isFrozen() && (ps->getLastFrameNumber() >= (nv.getFrameStamp()->getFrameNumber() - 1) || !ps->getFreezeOnCull()))
                         {