diff --git a/include/boost/polygon/polygon.hpp b/include/boost/polygon/polygon.hpp
index 10104565da..2591156309 100644
--- a/include/boost/polygon/polygon.hpp
+++ b/include/boost/polygon/polygon.hpp
@@ -23,6 +23,7 @@
 
 #include "transform.hpp"
 #include "detail/transform_detail.hpp"
+#include "detail/polygon_sort_adaptor.hpp"
 
 //interval
 #include "interval_data.hpp"