diff -Nur chrony-3.5.bck/examples/chronyd.service chrony-3.5/examples/chronyd.service
--- chrony-3.5.bck/examples/chronyd.service	2020-06-23 15:41:07.789042822 +0800
+++ chrony-3.5/examples/chronyd.service	2020-06-23 15:42:09.489819150 +0800
@@ -10,6 +10,7 @@
 PIDFile=/run/chrony/chronyd.pid
 EnvironmentFile=-/etc/sysconfig/chronyd
 ExecStart=/usr/sbin/chronyd $OPTIONS
+ExecStartPost=/usr/libexec/chrony-helper update-daemon
 PrivateTmp=yes
 ProtectHome=yes
 ProtectSystem=full