diff --git a/include/mapnik/json/geometry_grammar.hpp b/include/mapnik/json/geometry_grammar.hpp
index 416442161..157d0e6b1 100644
--- a/include/mapnik/json/geometry_grammar.hpp
+++ b/include/mapnik/json/geometry_grammar.hpp
@@ -117,8 +117,11 @@ struct close_path
     void operator() (T path) const
     {
         BOOST_ASSERT( path!=0 );
-        path->close_path();
-    }
+        if (path->size() > 2u) // to form a polygon ring we need at least 3 vertices
+        {
+            path->close_path();
+        }
+   }
 };
 
 struct cleanup