diff --git a/include/mapnik/geometry_impl.hpp b/include/mapnik/geometry_impl.hpp
index 62f549ce3..a0f5bd13f 100644
--- a/include/mapnik/geometry_impl.hpp
+++ b/include/mapnik/geometry_impl.hpp
@@ -20,6 +20,9 @@
  *
  *****************************************************************************/
 
+#ifndef MAPNIK_GEOMETRY_IMPL_HPP
+#define MAPNIK_GEOMETRY_IMPL_HPP
+
 #include <vector>
 #include <mapnik/util/variant.hpp>
 #include <mapnik/vertex.hpp>
@@ -469,3 +472,5 @@ struct vertex_processor
 };
 
 }}
+
+#endif //MAPNIK_GEOMETRY_IMPL_HPP