diff --git a/include/asio/detail/win_mutex.hpp b/include/asio/detail/win_mutex.hpp
index 015d1dbfbe..a11eb045ad 100644
--- a/include/asio/detail/win_mutex.hpp
+++ b/include/asio/detail/win_mutex.hpp
@@ -22,7 +22,9 @@
 #include "asio/detail/noncopyable.hpp"
 #include "asio/detail/scoped_lock.hpp"
 #include "asio/detail/socket_types.hpp"
+#ifndef _USING_V110_SDK71_
 #include <synchapi.h>
+#endif
 
 #include "asio/detail/push_options.hpp"