diff --git a/include/osgParticle/Emitter b/include/osgParticle/Emitter
index 935f14cea..fbce814c0 100644
--- a/include/osgParticle/Emitter
+++ b/include/osgParticle/Emitter
@@ -30,7 +30,7 @@ namespace osgParticle
 
         virtual const char *libraryName() const { return "osgParticle"; }
         virtual const char *className() const { return "Emitter"; }
-        virtual bool isSameKindAs(const osg::Object *obj) { return dynamic_cast<const Emitter*>(obj) != 0; }
+        virtual bool isSameKindAs(const osg::Object *obj) const { return dynamic_cast<const Emitter*>(obj) != 0; }
         virtual void accept(osg::NodeVisitor& nv) { if (nv.validNodeMask(*this)) { nv.pushOntoNodePath(this); nv.apply(*this); nv.popFromNodePath(); } }
         
         /// Get the particle template.
diff --git a/include/osgParticle/ParticleProcessor b/include/osgParticle/ParticleProcessor
index 8a193100d..e00533ec7 100644
--- a/include/osgParticle/ParticleProcessor
+++ b/include/osgParticle/ParticleProcessor
@@ -38,7 +38,7 @@ namespace osgParticle
         ParticleProcessor(const ParticleProcessor &copy, const osg::CopyOp &copyop = osg::CopyOp::SHALLOW_COPY);
 
         virtual const char *className() const { return "ParticleProcessor"; }
-        virtual bool isSameKindAs(const osg::Object *obj) { return dynamic_cast<const ParticleProcessor*>(obj) != 0; }
+        virtual bool isSameKindAs(const osg::Object *obj) const { return dynamic_cast<const ParticleProcessor*>(obj) != 0; }
         virtual void accept(osg::NodeVisitor& nv) { if (nv.validNodeMask(*this)) { nv.pushOntoNodePath(this); nv.apply(*this); nv.popFromNodePath(); } }        
         
         /// Get the reference frame.
diff --git a/include/osgParticle/Program b/include/osgParticle/Program
index 8eeabc449..6a3e1170a 100644
--- a/include/osgParticle/Program
+++ b/include/osgParticle/Program
@@ -30,7 +30,7 @@ namespace osgParticle
 
         virtual const char *libraryName() const { return "osgParticle"; }
         virtual const char *className() const { return "Program"; }
-        virtual bool isSameKindAs(const osg::Object *obj) { return dynamic_cast<const Program*>(obj) != 0; }
+        virtual bool isSameKindAs(const osg::Object *obj) const { return dynamic_cast<const Program*>(obj) != 0; }
         virtual void accept(osg::NodeVisitor& nv) { if (nv.validNodeMask(*this)) { nv.pushOntoNodePath(this); nv.apply(*this); nv.popFromNodePath(); } }
 
     protected: