diff --git a/include/boost/mpl/aux_/preprocessor/def_params_tail.hpp b/include/boost/mpl/aux_/preprocessor/def_params_tail.hpp
index 0ef5da4..c8e564c 100644
--- a/include/boost/mpl/aux_/preprocessor/def_params_tail.hpp
+++ b/include/boost/mpl/aux_/preprocessor/def_params_tail.hpp
@@ -21,6 +21,8 @@
 #include "boost/mpl/aux_/config/dtp.hpp"
 #include "boost/mpl/aux_/config/preprocessor.hpp"
 
+#include "boost/preprocessor/comma_if.hpp"
+#include "boost/preprocessor/logical/and.hpp"
 #include "boost/preprocessor/identity.hpp"
 #include "boost/preprocessor/empty.hpp"
 
@@ -47,9 +49,11 @@
     /**/
 
 #   define BOOST_MPL_PP_DEF_PARAMS_TAIL_DELAY_2(i, n, param, value_func) \
-    , BOOST_MPL_PP_DEF_PARAMS_TAIL_##i(n,param,value_func) \
+    BOOST_PP_COMMA_IF(BOOST_PP_AND(i,n)) \
+    BOOST_MPL_PP_DEF_PARAMS_TAIL_##i(n,param,value_func) \
     /**/
 
+#   define BOOST_MPL_PP_DEF_PARAMS_TAIL_0(i,p,v) BOOST_MPL_PP_FILTER_PARAMS_##i(p##1 v(),p##2 v(),p##3 v(),p##4 v(),p##5 v(),p##6 v(),p##7 v(),p##8 v(),p##9 v())
 #   define BOOST_MPL_PP_DEF_PARAMS_TAIL_1(i,p,v) BOOST_MPL_PP_FILTER_PARAMS_##i(p##2 v(),p##3 v(),p##4 v(),p##5 v(),p##6 v(),p##7 v(),p##8 v(),p##9 v(),p1)
 #   define BOOST_MPL_PP_DEF_PARAMS_TAIL_2(i,p,v) BOOST_MPL_PP_FILTER_PARAMS_##i(p##3 v(),p##4 v(),p##5 v(),p##6 v(),p##7 v(),p##8 v(),p##9 v(),p1,p2)
 #   define BOOST_MPL_PP_DEF_PARAMS_TAIL_3(i,p,v) BOOST_MPL_PP_FILTER_PARAMS_##i(p##4 v(),p##5 v(),p##6 v(),p##7 v(),p##8 v(),p##9 v(),p1,p2,p3)
@@ -70,7 +74,8 @@
 #   include "boost/preprocessor/cat.hpp"
 
 #   define BOOST_MPL_PP_AUX_TAIL_PARAM_FUNC(unused, i, op) \
-    , BOOST_PP_CAT( \
+    BOOST_PP_COMMA_IF(i) \
+    BOOST_PP_CAT( \
           BOOST_PP_TUPLE_ELEM(3, 1, op) \
         , BOOST_PP_ADD_D(1, i, BOOST_PP_INC(BOOST_PP_TUPLE_ELEM(3, 0, op))) \
         ) BOOST_PP_TUPLE_ELEM(3, 2, op)() \
diff --git a/include/boost/mpl/aux_/preprocessor/partial_spec_params.hpp b/include/boost/mpl/aux_/preprocessor/partial_spec_params.hpp
new file mode 100644
index 0000000..75db7a0
--- /dev/null
+++ b/include/boost/mpl/aux_/preprocessor/partial_spec_params.hpp
@@ -0,0 +1,35 @@
+//-----------------------------------------------------------------------------
+// boost mpl/aux_/preprocessor/partial_spec_params.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2000-02
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_AUX_PREPROCESSOR_PARTIAL_SPEC_PARAMS_HPP_INCLUDED
+#define BOOST_MPL_AUX_PREPROCESSOR_PARTIAL_SPEC_PARAMS_HPP_INCLUDED
+
+#include "boost/mpl/limits/arity.hpp"
+#include "boost/mpl/aux_/preprocessor/params.hpp"
+#include "boost/mpl/aux_/preprocessor/enum.hpp"
+#include "boost/mpl/aux_/preprocessor/sub.hpp"
+#include "boost/preprocessor/comma_if.hpp"
+
+#define BOOST_MPL_PP_PARTIAL_SPEC_PARAMS(n, param, def) \
+BOOST_MPL_PP_PARAMS(n, param) \
+BOOST_PP_COMMA_IF(BOOST_MPL_PP_SUB(BOOST_MPL_METAFUNCTION_MAX_ARITY,n)) \
+BOOST_MPL_PP_ENUM( \
+      BOOST_MPL_PP_SUB(BOOST_MPL_METAFUNCTION_MAX_ARITY,n) \
+    , def \
+    ) \
+/**/
+
+#endif // BOOST_MPL_AUX_PREPROCESSOR_PARTIAL_SPEC_PARAMS_HPP_INCLUDED