diff --git a/internal/alerts/alerts.go b/internal/alerts/alerts.go
index 37ddb50b2..201ed0649 100644
--- a/internal/alerts/alerts.go
+++ b/internal/alerts/alerts.go
@@ -8726,9 +8726,20 @@ func (m *Manager) LoadActiveAlerts() error {
 			continue
 		}
 
-		// Skip acknowledged alerts older than 1 hour
+		// Skip acknowledged alerts older than 1 hour from activeAlerts,
+		// but still preserve the ackState so if the same alert reappears
+		// (e.g., backup-age alerts) it won't retrigger notifications.
 		if alert.Acknowledged && alert.AckTime != nil && now.Sub(*alert.AckTime) > time.Hour {
-			log.Debug().Str("alertID", alert.ID).Msg("Skipping old acknowledged alert")
+			log.Debug().Str("alertID", alert.ID).Msg("Skipping old acknowledged alert from activeAlerts but preserving ackState")
+			ackTime := alert.StartTime
+			if alert.AckTime != nil {
+				ackTime = *alert.AckTime
+			}
+			m.ackState[alert.ID] = ackRecord{
+				acknowledged: true,
+				user:         alert.AckUser,
+				time:         ackTime,
+			}
 			continue
 		}
 
diff --git a/internal/alerts/alerts_test.go b/internal/alerts/alerts_test.go
index 00b18add1..ca262867a 100644
--- a/internal/alerts/alerts_test.go
+++ b/internal/alerts/alerts_test.go
@@ -15343,10 +15343,22 @@ func TestLoadActiveAlerts(t *testing.T) {
 
 		m.mu.RLock()
 		_, exists := m.activeAlerts["old-ack-alert"]
+		ackRecord, ackExists := m.ackState["old-ack-alert"]
 		m.mu.RUnlock()
 
 		if exists {
-			t.Error("old acknowledged alert (>1h) should be skipped during load")
+			t.Error("old acknowledged alert (>1h) should be skipped from activeAlerts")
+		}
+
+		// But ackState should be preserved so the alert doesn't retrigger if it reappears
+		if !ackExists {
+			t.Error("ackState should be preserved for old acknowledged alerts to prevent retriggering")
+		}
+		if ackExists && !ackRecord.acknowledged {
+			t.Error("ackState.acknowledged should be true")
+		}
+		if ackExists && ackRecord.user != "testuser" {
+			t.Errorf("ackState.user should be 'testuser', got %q", ackRecord.user)
 		}
 	})