diff --git a/include/mapnik/json/extract_bounding_box_grammar_impl.hpp b/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
index bdc1b98b2..6be94a954 100644
--- a/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
+++ b/include/mapnik/json/extract_bounding_box_grammar_impl.hpp
@@ -64,10 +64,10 @@ struct push_box_impl
     template <typename T0, typename T1, typename T2, typename T3>
     void operator() (T0 & boxes, T1 const& begin, T2 const& box, T3 const& range) const
     {
-        if (box.valid()) boxes.emplace_back(box,
-                                            std::make_pair(std::distance(begin,
-                                                                         range.begin()),
-                                                           std::distance(range.begin(), range.end())));
+        boxes.emplace_back(box,
+                           std::make_pair(std::distance(begin,
+                                                        range.begin()),
+                                          std::distance(range.begin(), range.end())));
     }
 };