diff --git a/src/osg/Referenced.cpp b/src/osg/Referenced.cpp
index 994f577c8..9fc3523e5 100644
--- a/src/osg/Referenced.cpp
+++ b/src/osg/Referenced.cpp
@@ -276,7 +276,7 @@ ObserverSet* Referenced::getOrCreateObserverSet() const
         if (!_observerSet)
         {
             _observerSet = new ObserverSet(this);
-            _observerSet->ref();
+            static_cast<ObserverSet*>(_observerSet)->ref();
         }
         return static_cast<ObserverSet*>(_observerSet);
     }