diff --git a/Python/thread_nt.h b/Python/thread_nt.h
index 3a01a7fe327c8f..e078b98be3cdf4 100644
--- a/Python/thread_nt.h
+++ b/Python/thread_nt.h
@@ -289,6 +289,7 @@ PyThread_exit_thread(void)
     if (!initialized)
         exit(0);
     _endthreadex(0);
+    Py_UNREACHABLE();
 }
 
 void _Py_NO_RETURN