diff --git a/src/load_map.cpp b/src/load_map.cpp
index 74f7b3824..1a4522322 100644
--- a/src/load_map.cpp
+++ b/src/load_map.cpp
@@ -377,25 +377,15 @@ void map_parser::parse_map_include(Map & map, xml_node const& node)
                 {
                     if (p.is("Parameter"))
                     {
-                        bool is_string = true;
-                        boost::optional<std::string> type = p.get_opt_attr<std::string>("type");
-                        if (type)
-                        {
-                            if (*type == "int")
-                            {
-                                is_string = false;
-                                params[p.get_attr<std::string>("name")] = p.get_value<mapnik::value_integer>();
-                            }
-                            else if (*type == "float")
-                            {
-                                is_string = false;
-                                params[p.get_attr<std::string>("name")] = p.get_value<mapnik::value_double>();
-                            }
-                        }
-                        if (is_string)
-                        {
-                            params[p.get_attr<std::string>("name")] = p.get_text();
-                        }
+                        std::string val = p.get_text();
+                        std::string key = p.get_attr<std::string>("name");
+                        mapnik::value_bool b;
+                        mapnik::value_integer i;
+                        mapnik::value_double d;
+                        if (mapnik::util::string2bool(val,b)) params[key] = b;
+                        else if (mapnik::util::string2int(val,i)) params[key] = i;
+                        else if (mapnik::util::string2double(val,d)) params[key] = d;
+                        else params[key] = val;
                     }
                 }
             }
diff --git a/src/save_map.cpp b/src/save_map.cpp
index 27eb75518..136fdf98b 100644
--- a/src/save_map.cpp
+++ b/src/save_map.cpp
@@ -488,36 +488,6 @@ void serialize_datasource( ptree & layer_node, datasource_ptr datasource)
     }
 }
 
-class serialize_type : public util::static_visitor<>
-{
-public:
-    serialize_type( boost::property_tree::ptree & node):
-        node_(node) {}
-
-    void operator () ( mapnik::value_integer ) const
-    {
-        node_.put("<xmlattr>.type", "int" );
-    }
-
-    void operator () ( mapnik::value_double ) const
-    {
-        node_.put("<xmlattr>.type", "float" );
-    }
-
-    void operator () ( std::string const& ) const
-    {
-        node_.put("<xmlattr>.type", "string" );
-    }
-
-    void operator () ( mapnik::value_null ) const
-    {
-        node_.put("<xmlattr>.type", "string" );
-    }
-
-private:
-    boost::property_tree::ptree & node_;
-};
-
 void serialize_parameters( ptree & map_node, mapnik::parameters const& params)
 {
     if (params.size()) {
@@ -531,7 +501,6 @@ void serialize_parameters( ptree & map_node, mapnik::parameters const& params)
                                                         boost::property_tree::ptree()))->second;
             param_node.put("<xmlattr>.name", p.first );
             param_node.put_value( p.second );
-            util::apply_visitor(serialize_type(param_node),p.second);
         }
     }
 }
diff --git a/tests/python_tests/extra_map_props_test.py b/tests/python_tests/extra_map_props_test.py
index 06d659682..e7ffba5d4 100644
--- a/tests/python_tests/extra_map_props_test.py
+++ b/tests/python_tests/extra_map_props_test.py
@@ -13,13 +13,30 @@ def setup():
 def test_arbitrary_parameters_attached_to_map():
     m = mapnik.Map(256,256)
     mapnik.load_map(m,'../data/good_maps/extra_arbitary_map_parameters.xml')
-    eq_(len(m.parameters),6)
+    eq_(len(m.parameters),5)
     eq_(m.parameters['key'],'value2')
     eq_(m.parameters['key3'],'value3')
     eq_(m.parameters['unicode'],u'iván')
     eq_(m.parameters['integer'],10)
     eq_(m.parameters['decimal'],.999)
-    eq_(m.parameters['number-as-string'],u'.9998')
+    m2 = mapnik.Map(256,256)
+    for k,v in m.parameters:
+        m2.parameters.append(mapnik.Parameter(k,v))
+    eq_(len(m2.parameters),5)
+    eq_(m2.parameters['key'],'value2')
+    eq_(m2.parameters['key3'],'value3')
+    eq_(m2.parameters['unicode'],u'iván')
+    eq_(m2.parameters['integer'],10)
+    eq_(m2.parameters['decimal'],.999)
+    map_string = mapnik.save_map_to_string(m)
+    m3 = mapnik.Map(256,256)
+    mapnik.load_map_from_string(m3,map_string)
+    eq_(len(m3.parameters),5)
+    eq_(m3.parameters['key'],'value2')
+    eq_(m3.parameters['key3'],'value3')
+    eq_(m3.parameters['unicode'],u'iván')
+    eq_(m3.parameters['integer'],10)
+    eq_(m3.parameters['decimal'],.999)
 
 
 def test_serializing_arbitrary_parameters():