diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 2638bdc..a405812 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -1746,6 +1746,8 @@
 	Py_INCREF(SelectError);
 	PyModule_AddObject(m, "error", SelectError);
 
+	PyModule_AddIntConstant(m, "PIPE_BUF", PIPE_BUF);
+
 #if defined(HAVE_POLL)
 #ifdef __APPLE__
 	if (select_have_broken_poll()) {