diff --git a/include/boost/program_options/detail/cmdline.hpp b/include/boost/program_options/detail/cmdline.hpp
index ce212ee..36eb988 100644
--- a/include/boost/program_options/detail/cmdline.hpp
+++ b/include/boost/program_options/detail/cmdline.hpp
@@ -87,9 +87,6 @@ namespace boost { namespace program_options { namespace detail {
         std::vector<option> parse_terminator(
             std::vector<std::string>& args);
 
-
-#if 0
-
         /** Set additional parser. This will be called for each token
             of command line. If first string in pair is not empty,
             then the token is considered matched by this parser,
@@ -100,8 +97,6 @@ namespace boost { namespace program_options { namespace detail {
         */
         void set_additional_parser(additional_parser p);
 
-#endif
-
         void check_style(int style) const;
 
 
diff --git a/src/cmdline.cpp b/src/cmdline.cpp
index be5bc31..441ea88 100644
--- a/src/cmdline.cpp
+++ b/src/cmdline.cpp
@@ -163,6 +163,7 @@ namespace boost { namespace program_options { namespace detail {
         //
         // When some 'style parser' consumes some input 
         // we start with the first style parser. 
+        assert(m_desc);
 
         vector<style_parser> style_parsers;      
         if (style & allow_long)
@@ -185,6 +186,18 @@ namespace boost { namespace program_options { namespace detail {
         vector<option> result;
         while(!args.empty())
         {
+            if (m_additional_parser) {
+                pair<string, string> r = m_additional_parser(args[0]);
+                if (!r.first.empty()) {
+                    option next;
+                    next.string_key = r.first;
+                    next.value.push_back(r.second);
+                    result.push_back(next);
+                    args.erase(args.begin());
+                    continue;
+                }
+            }
+
             bool ok = false;
             for(unsigned i = 0; i < style_parsers.size(); ++i)
             {
@@ -419,17 +432,11 @@ namespace boost { namespace program_options { namespace detail {
         return result;
     }
 
-
-
-
-#if 0
-
     void 
     cmdline::set_additional_parser(additional_parser p)
     {
         m_additional_parser = p;
     }
-#endif
 
 
 }}}
diff --git a/test/cmdline_test.cpp b/test/cmdline_test.cpp
index 14c0d9d..1729ae5 100644
--- a/test/cmdline_test.cpp
+++ b/test/cmdline_test.cpp
@@ -431,6 +431,41 @@ void test_prefix()
     test_cmdline("foo*=", style, test_cases1);
 }
 
+
+pair<string, string> at_option_parser(string const&s)
+{
+    if ('@' == s[0])
+        return std::make_pair(string("response-file"), s.substr(1));
+    else
+        return pair<string, string>();
+}
+
+
+void test_additional_parser()
+{
+    options_description desc;
+    desc.add_options()
+        ("response-file", value<string>(), "response file")
+        ("foo", value<int>(), "foo")
+        ;
+
+    vector<string> input;
+    input.push_back("@config");
+    input.push_back("--foo=1");
+
+    detail::cmdline cmd(input, command_line_style::default_style);
+    cmd.set_options_description(desc);
+    cmd.set_additional_parser(at_option_parser);
+
+    vector<option> result = cmd.run();
+
+    BOOST_REQUIRE(result.size() == 2);
+    BOOST_CHECK_EQUAL(result[0].string_key, "response-file");
+    BOOST_CHECK_EQUAL(result[0].value[0], "config");
+    BOOST_CHECK_EQUAL(result[1].string_key, "foo");
+    BOOST_CHECK_EQUAL(result[1].value[0], "1");    
+}
+
 int test_main(int ac, char* av[])
 {
     test_long_options();
@@ -440,6 +475,7 @@ int test_main(int ac, char* av[])
     test_guessing();
     test_arguments();
     test_prefix();
+    test_additional_parser();
 
     return 0;
 }