diff --git a/resources/prometheus/prometheus-rules.yaml b/resources/prometheus/prometheus-rules.yaml
index b2f33f5..6521231 100644
--- a/resources/prometheus/prometheus-rules.yaml
+++ b/resources/prometheus/prometheus-rules.yaml
@@ -128,6 +128,22 @@ spec:
             summary: "Fleetshard synchronizer container `{{ $labels.pod }}/{{ $labels.container }}` in namespace `{{ $labels.namespace }}` restarted more than 3 times."
             description: "Fleetshard synchronizer container `{{ $labels.pod }}/{{ $labels.container }}` in namespace `{{ $labels.namespace }}` has restarted more than 3 times during the last 30 minutes."
             sop_url: "https://gitlab.cee.redhat.com/stackrox/acs-managed-service-runbooks/blob/master/sops/dp-005-fleetshard-sync-unavailable.md"
+        - alert: RHACSFleetshardCertificateExpiryCritical
+          expr: |
+            acs_fleetshard_certificate_expiration_timestamp <= 1 * 24 * 60 * 60 + time()
+          labels:
+            severity: critical
+          annotations:
+            summary: "Certificate expiring very soon: `{{ $labels.exported_namespace }}/{{ $labels.secret }}/{{ $labels.data_key }}`."
+            description: "Certificate `{{ $labels.exported_namespace }}/{{ $labels.secret }}/{{ $labels.data_key }}` expires on {{ humanizeTimestamp $value}}."
+        - alert: RHACSFleetshardCertificateExpiryWarning
+          expr: |
+            acs_fleetshard_certificate_expiration_timestamp <= 7* 24 * 60 * 60 + time()
+          labels:
+            severity: warning
+          annotations:
+            summary: "Certificate expiring soon: `{{ $labels.exported_namespace }}/{{ $labels.secret }}/{{ $labels.data_key }}`."
+            description: "Certificate `{{ $labels.exported_namespace }}/{{ $labels.secret }}/{{ $labels.data_key }}` expires on {{ humanizeTimestamp $value}}."
         - alert: RHACSFleetshardSyncReconciliationErrors
           expr: |
             acs_fleetshard_central_errors_per_reconciliations:ratio_rate10m > 0.10
diff --git a/resources/prometheus/unit_tests/RHACSFleetschardCertificateExpiring.yaml b/resources/prometheus/unit_tests/RHACSFleetschardCertificateExpiring.yaml
new file mode 100644
index 0000000..57516c5
--- /dev/null
+++ b/resources/prometheus/unit_tests/RHACSFleetschardCertificateExpiring.yaml
@@ -0,0 +1,51 @@
+rule_files:
+  - /tmp/prometheus-rules-test.yaml
+
+evaluation_interval: 1m
+
+tests:
+  - interval: 1d
+    input_series:
+      - series: acs_fleetshard_certificate_expiration_timestamp{exported_namespace="rhacs-00000000000000000000", secret="secret", data_key="key"}
+        values: "691200+0x15" # equals to 8 days
+
+    alert_rule_test:
+      - eval_time: 0
+        alertname: RHACSFleetshardCertificateExpiryWarning
+        exp_alerts: [ ]
+      - eval_time: 3d
+        alertname: RHACSFleetshardCertificateExpiryWarning
+        exp_alerts:
+          - exp_labels:
+              alertname: RHACSFleetshardCertificateExpiryWarning
+              exported_namespace: rhacs-00000000000000000000
+              secret: secret
+              data_key: key
+              severity: warning
+            exp_annotations:
+              summary: "Certificate expiring soon: `rhacs-00000000000000000000/secret/key`."
+              description: "Certificate `rhacs-00000000000000000000/secret/key` expires on 1970-01-09 00:00:00 +0000 UTC."
+      - eval_time: 7d
+        alertname: RHACSFleetshardCertificateExpiryCritical
+        exp_alerts:
+          - exp_labels:
+              alertname: RHACSFleetshardCertificateExpiryCritical
+              exported_namespace: rhacs-00000000000000000000
+              secret: secret
+              data_key: key
+              severity: critical
+            exp_annotations:
+              summary: "Certificate expiring very soon: `rhacs-00000000000000000000/secret/key`."
+              description: "Certificate `rhacs-00000000000000000000/secret/key` expires on 1970-01-09 00:00:00 +0000 UTC."
+      - eval_time: 10d
+        alertname: RHACSFleetshardCertificateExpiryCritical
+        exp_alerts:
+          - exp_labels:
+              alertname: RHACSFleetshardCertificateExpiryCritical
+              exported_namespace: rhacs-00000000000000000000
+              secret: secret
+              data_key: key
+              severity: critical
+            exp_annotations:
+              summary: "Certificate expiring very soon: `rhacs-00000000000000000000/secret/key`."
+              description: "Certificate `rhacs-00000000000000000000/secret/key` expires on 1970-01-09 00:00:00 +0000 UTC."