diff --git a/include/wx/mac/carbon/listbox.h b/include/wx/mac/carbon/listbox.h
index f94cff95b9..d5aa80277d 100644
--- a/include/wx/mac/carbon/listbox.h
+++ b/include/wx/mac/carbon/listbox.h
@@ -138,8 +138,6 @@ public:
     wxArrayString   m_stringArray ;
     wxListDataArray m_dataArray ;
     wxArrayInt      m_selectionPreImage ;
-    wxArrayLong     m_idArray ;
-    wxUint32        m_nextId ;
     
     void            MacSetRedraw( bool doDraw ) ;
 protected: