diff --git a/include/thread b/include/thread
index b6b7000..d81e853 100644
--- a/include/thread
+++ b/include/thread
@@ -227,7 +227,7 @@
     _LIBCPP_INLINE_VISIBILITY
     __thread_id(pthread_t __id) : __id_(__id) {}
 
-    friend __thread_id this_thread::get_id();
+    friend __thread_id this_thread::get_id() _NOEXCEPT;
     friend class _LIBCPP_VISIBLE thread;
     friend struct _LIBCPP_VISIBLE hash<__thread_id>;
 };