diff --git a/include/boost/python/detail/defaults_gen.hpp b/include/boost/python/detail/defaults_gen.hpp
index 9a43ed9b..b131269d 100644
--- a/include/boost/python/detail/defaults_gen.hpp
+++ b/include/boost/python/detail/defaults_gen.hpp
@@ -20,6 +20,7 @@
 #include <boost/preprocessor/stringize.hpp>
 #include <boost/preprocessor/inc.hpp>
 #include <boost/preprocessor/empty.hpp>
+#include <boost/preprocessor/comma_if.hpp>
 #include <boost/config.hpp>
 #include <boost/python/detail/type_list_utils.hpp>
 
@@ -107,7 +108,7 @@ struct func_stubs_base {};
 #define BPL_IMPL_MEM_FUNC_WRAPPER_GEN(INDEX, DATA)                              \
     static RT BOOST_PP_CAT(func_, INDEX)                                        \
     (                                                                           \
-        ClassT& obj,                                                            \
+        ClassT& obj BOOST_PP_COMMA_IF(INDEX)                                    \
         BOOST_PP_ENUM                                                           \
         (                                                                       \
             BOOST_PP_ADD(BOOST_PP_TUPLE_ELEM(3, 1, DATA), INDEX),               \