diff --git a/openstack/limes/alerts/openstack/api.alerts b/openstack/limes/alerts/openstack/api.alerts
index c5cf4e7e45..8997b302d2 100644
--- a/openstack/limes/alerts/openstack/api.alerts
+++ b/openstack/limes/alerts/openstack/api.alerts
@@ -309,3 +309,19 @@ groups:
         The actual quota is {{ $value }}, which differs from the configured quota override.
         Please check the Resource Management UI of the project. If the quota override cannot be enforced because commitments or usage are higher than it, the override needs to be removed (from quota-overrides.yaml in cc/secrets).
         The opposite case (a quota below the configured override) needs to be triaged by a Limes expert.
+
+  - alert: OpenstackLimesCinderCapacityWithUnknownVolumeType
+    # NOTE: This alert is disabled in QA because Tempest runs create private volume types all the time.
+    expr: 'sum by (project_id) ((liquid_cinder_snapshots_with_unknown_volume_type_size{region!~"qa.*"} > 0) + (liquid_cinder_volumes_with_unknown_volume_type_size{region!~"qa.*"} > 0))
+    for: 15m
+    labels:
+      severity: warning
+      support_group: containers
+      tier: os
+      service: limes
+    annotations:
+      summary: Cinder capacity with unknown volume type
+      description: |
+        The project {{ $labels.project_id }} contains Cinder volumes and/or snapshots whose volume types are not known to Limes (which usually means that they are private).
+        This might be bad because payload without a known volume type is not billed.
+        Please check the log of the liquid-cinder pod in the limes namespace to find out which volumes/snapshots are problematic and which volume types they are using.