diff --git a/include/turtle/detail/sequence_impl.hpp b/include/turtle/detail/sequence_impl.hpp
index bcb6d33..ac40080 100644
--- a/include/turtle/detail/sequence_impl.hpp
+++ b/include/turtle/detail/sequence_impl.hpp
@@ -10,6 +10,7 @@
 #define MOCK_SEQUENCE_IMPL_HPP_INCLUDED
 
 #include "../config.hpp"
+#include "mutex.hpp"
 #include <boost/noncopyable.hpp>
 #include <boost/shared_ptr.hpp>
 #include <algorithm>
diff --git a/include/turtle/sequence.hpp b/include/turtle/sequence.hpp
index f3009ca..051d219 100644
--- a/include/turtle/sequence.hpp
+++ b/include/turtle/sequence.hpp
@@ -10,8 +10,8 @@
 #define MOCK_SEQUENCE_HPP_INCLUDED
 
 #include "config.hpp"
-#include "detail/sequence_impl.hpp"
 #include <boost/make_shared.hpp>
+#include "detail/sequence_impl.hpp"
 
 namespace mock
 {