diff --git a/lib/charms/prometheus_k8s/v1/prometheus_remote_write.py b/lib/charms/prometheus_k8s/v1/prometheus_remote_write.py
index 049c8faf..67809d41 100644
--- a/lib/charms/prometheus_k8s/v1/prometheus_remote_write.py
+++ b/lib/charms/prometheus_k8s/v1/prometheus_remote_write.py
@@ -749,6 +749,7 @@ def alerts(self) -> dict:
 
             _, errmsg = self._tool.validate_alert_rules(alert_rules)
             if errmsg:
+                logger.error(f"Invalid alert rule file: {errmsg}")
                 if self._charm.unit.is_leader():
                     data = json.loads(relation.data[self._charm.app].get("event", "{}"))
                     data["errors"] = errmsg