diff --git a/pkg/services/ngalert/provisioning/alert_rules.go b/pkg/services/ngalert/provisioning/alert_rules.go
index cbe638d2276..b673be172f0 100644
--- a/pkg/services/ngalert/provisioning/alert_rules.go
+++ b/pkg/services/ngalert/provisioning/alert_rules.go
@@ -467,6 +467,10 @@ func (service *AlertRuleService) GetAlertGroupsWithFolderTitle(ctx context.Conte
 		namespaces[r.NamespaceUID] = append(namespaces[r.NamespaceUID], &groupKey)
 	}
 
+	if len(namespaces) == 0 {
+		return []models.AlertRuleGroupWithFolderTitle{}, nil
+	}
+
 	dq := dashboards.GetDashboardsQuery{
 		DashboardUIDs: nil,
 	}