diff --git a/src/osgPlugins/ply/ReaderWriterPLY.cpp b/src/osgPlugins/ply/ReaderWriterPLY.cpp
index 18c21f5a5..62ab80554 100644
--- a/src/osgPlugins/ply/ReaderWriterPLY.cpp
+++ b/src/osgPlugins/ply/ReaderWriterPLY.cpp
@@ -44,7 +44,7 @@ public:
         supportsExtension("ply","Stanford Triangle Format");
     }
 
-    virtual const char* className() { return "ReaderWriterPLY"; }
+    virtual const char* className() const { return "ReaderWriterPLY"; }
     virtual ReadResult readNode(const std::string& fileName, const osgDB::ReaderWriter::Options*) const;
 protected:
 };