diff --git a/helper/ccnb-parser/visitors/ccnb-parser-visitor.h b/helper/ccnb-parser/visitors/ccnb-parser-visitor.h
index 24212d4..e0fac3a 100644
--- a/helper/ccnb-parser/visitors/ccnb-parser-visitor.h
+++ b/helper/ccnb-parser/visitors/ccnb-parser-visitor.h
@@ -44,6 +44,8 @@
   virtual boost::any visit (Dtag&,  boost::any)=0; ///< \brief Method accepting DTAG block  
   virtual boost::any visit (Dattr&, boost::any)=0; ///< \brief Method accepting DATTR block 
   virtual boost::any visit (Ext&,   boost::any)=0; ///< \brief Method accepting EXT block
+
+  virtual ~Visitor () { }
 };                                                
                                                   
 }