--- ceph-15.2.8/src/common/ceph_time.h.orig	2020-12-24 06:23:32.605762289 -0500
+++ ceph-15.2.8/src/common/ceph_time.h	2020-12-24 13:50:14.304877611 -0500
@@ -18,6 +18,7 @@
 #include <chrono>
 #include <iostream>
 #include <string>
+#include <optional>
 #include <sys/time.h>
 
 #include "include/ceph_assert.h"