diff --git a/bindings/python/mapnik_map.cpp b/bindings/python/mapnik_map.cpp
index e12105d8e..11a765daf 100644
--- a/bindings/python/mapnik_map.cpp
+++ b/bindings/python/mapnik_map.cpp
@@ -148,7 +148,7 @@ void export_map()
     
    class_<Map>("Map","The map object.",init<int,int,optional<std::string const&> >(
 #if BOOST_VERSION >= 103500
-                  args("self","width","height","srs"),
+                  ( args("self"),arg("width"),arg("height"),arg("srs") ),
 #endif
                   "Create a Map with a width and height as integers and, optionally,\n"
                   "an srs string either with a Proj.4 epsg code ('+init=epsg:<code>')\n"