diff --git a/ansible/roles/stack/templates/gluetun-endpoint-watch.timer.j2 b/ansible/roles/stack/templates/gluetun-endpoint-watch.timer.j2
index 9c97558..3186755 100644
--- a/ansible/roles/stack/templates/gluetun-endpoint-watch.timer.j2
+++ b/ansible/roles/stack/templates/gluetun-endpoint-watch.timer.j2
@@ -2,8 +2,10 @@
 Description=Run gluetun endpoint watch every 5 minutes
 
 [Timer]
+# Every 5 minutes wall-clock (more reliable than OnUnitActiveSec alone)
+OnCalendar=*:0/5
+# Also soon after boot
 OnBootSec=2min
-OnUnitActiveSec=5min
 AccuracySec=30s
 Persistent=true
 Unit=gluetun-endpoint-watch.service