diff --git a/parallel_hashmap/phmap_base.h b/parallel_hashmap/phmap_base.h
index fd75af6..4ff5f07 100644
--- a/parallel_hashmap/phmap_base.h
+++ b/parallel_hashmap/phmap_base.h
@@ -5137,6 +5137,8 @@ public:
     };
 #endif
 
+#endif // BOOST_THREAD_SHARED_MUTEX_HPP
+
 // --------------------------------------------------------------------------
 //         std::shared_mutex support (read and write lock support)
 // --------------------------------------------------------------------------
@@ -5158,8 +5160,6 @@ public:
     };
 #endif // PHMAP_HAVE_SHARED_MUTEX
 
-#endif // BOOST_THREAD_SHARED_MUTEX_HPP
-
 
 }  // phmap