diff --git a/apps/k8s01/blog/slo.yaml b/apps/k8s01/blog/slo.yaml
index c65a3569f48be88e7ee8b259bdd9470bba6308d4..df9221450ce29aab00be398b3f3c4f3958c2716b 100644
--- a/apps/k8s01/blog/slo.yaml
+++ b/apps/k8s01/blog/slo.yaml
@@ -11,7 +11,7 @@ spec:
       description: "Blog: SLO based on availability for HTTP request responses."
       sli:
         events:
-          errorQuery: sum(rate(nginx_ingress_controller_requests{exported_namespace="blog",ingress="blog",status=~"(5..|429)"}[{{.window}}]))
+          errorQuery: sum(rate(nginx_ingress_controller_requests{exported_namespace="blog",ingress="blog",status=~"(5..|429)"}[{{.window}}])) OR vector(0)
           totalQuery: sum(rate(nginx_ingress_controller_requests{exported_namespace="blog",ingress="blog"}[{{.window}}])) > 0 OR vector(1)
       alerting:
         name: BlogHighErrorRate