diff --git a/systemd/system/petrified.timer b/systemd/system/petrified.timer
index aaf8c9d..b8e3b10 100644
--- a/systemd/system/petrified.timer
+++ b/systemd/system/petrified.timer
@@ -10,8 +10,7 @@ Description=Petrified update every 6 hours
 
 [Timer]
 Unit=petrified.service
-OnCalendar=6h
-AccuracySec=1h
+OnCalendar=0/6:00:00
 Persistent=true
 
 [Install]
diff --git a/systemd/user/petrified.timer b/systemd/user/petrified.timer
index 981f8b2..800c45f 100644
--- a/systemd/user/petrified.timer
+++ b/systemd/user/petrified.timer
@@ -10,8 +10,7 @@ Description=Petrified update every 6 hours as %u
 
 [Timer]
 Unit=petrified.service
-OnCalendar=6h
-AccuracySec=1h
+OnCalendar=0/6:00:00
 Persistent=true
 
 [Install]