diff --git a/src/Demos/osgparticle/osgparticle.cpp b/src/Demos/osgparticle/osgparticle.cpp
index 5ebe10ea4..b4f82202a 100644
--- a/src/Demos/osgparticle/osgparticle.cpp
+++ b/src/Demos/osgparticle/osgparticle.cpp
@@ -27,7 +27,7 @@ public:
 		: osgParticle::Operator(), center_(0, 0, 0), axis_(0, 0, 1), intensity_(0.1f) {}
 
 	VortexOperator(const VortexOperator &copy, const osg::CopyOp &copyop = osg::CopyOp::SHALLOW_COPY)
-		: Operator(copy, copyop), center_(copy.center_), axis_(copy.axis_), intensity_(copy.intensity_) {}
+		: osgParticle::Operator(copy, copyop), center_(copy.center_), axis_(copy.axis_), intensity_(copy.intensity_) {}
 
 	META_Object(osgParticle, VortexOperator);