diff --git a/turtle/detail/parent.hpp b/turtle/detail/parent.hpp
index f5637f0..e2a670b 100644
--- a/turtle/detail/parent.hpp
+++ b/turtle/detail/parent.hpp
@@ -10,8 +10,8 @@
 #define MOCK_PARENT_HPP_INCLUDED
 
 #include "type_name.hpp"
-#include <boost/optional.hpp>
 #include <boost/test/utils/basic_cstring/io.hpp>
+#include <boost/optional.hpp>
 #include <ostream>
 
 namespace mock
diff --git a/turtle/detail/root.hpp b/turtle/detail/root.hpp
index 2bac0e8..cae580e 100644
--- a/turtle/detail/root.hpp
+++ b/turtle/detail/root.hpp
@@ -14,6 +14,7 @@
 #include "context.hpp"
 #include "child.hpp"
 #include <boost/test/utils/trivial_singleton.hpp>
+#include <boost/optional.hpp>
 #include <ostream>
 #include <map>