diff --git a/turtle/detail/function.hpp b/turtle/detail/function.hpp
index f286694..007aa77 100644
--- a/turtle/detail/function.hpp
+++ b/turtle/detail/function.hpp
@@ -27,7 +27,6 @@
 #include <boost/preprocessor/comparison/equal.hpp>
 #include <boost/test/utils/basic_cstring/basic_cstring.hpp>
 #include <boost/test/utils/lazy_ostream.hpp>
-#include <boost/function_types/result_type.hpp>
 #include <boost/enable_shared_from_this.hpp>
 #include <boost/optional.hpp>
 #include <ostream>