diff --git a/src/basic_oarchive.cpp b/src/basic_oarchive.cpp
index 648e041c..9abd4946 100644
--- a/src/basic_oarchive.cpp
+++ b/src/basic_oarchive.cpp
@@ -25,7 +25,6 @@
 #include <boost/archive/detail/basic_oserializer.hpp>
 #include <boost/archive/detail/basic_pointer_oserializer.hpp>
 #include <boost/archive/detail/basic_oarchive.hpp>
-#include <boost/archive/detail/basic_archive_impl.hpp>
 #include <boost/archive/archive_exception.hpp>
 
 #ifdef BOOST_MSVC
@@ -45,11 +44,8 @@ namespace detail {
 class basic_oserializer;
 class basic_pointer_oserializer;
 
-class basic_oarchive_impl :
-    public basic_archive_impl
-{
+class basic_oarchive_impl {
     friend class basic_oarchive;
-
     unsigned int m_flags;
 
     //////////////////////////////////////////////////////////////////////
@@ -424,22 +420,6 @@ basic_oarchive::register_basic_serializer(const basic_oserializer & bos){
     pimpl->register_type(bos);
 }
 
-BOOST_ARCHIVE_DECL(void) 
-basic_oarchive::lookup_basic_helper(
-    const boost::serialization::extended_type_info * const eti,
-    shared_ptr<void> & sph
-){
-    pimpl->lookup_helper(eti, sph);
-}
-
-BOOST_ARCHIVE_DECL(void) 
-basic_oarchive::insert_basic_helper(
-    const boost::serialization::extended_type_info * const eti,
-    shared_ptr<void> & sph
-){
-    pimpl->insert_helper(eti, sph);
-}
-
 BOOST_ARCHIVE_DECL(unsigned int)
 basic_oarchive::get_library_version() const{
     return ARCHIVE_VERSION();