diff --git a/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cloudflared-tunnel-exits/http-exits.yaml b/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cloudflared-tunnel-exits/http-exits.yaml
index 77a0e97dd..e2795dbcc 100644
--- a/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cloudflared-tunnel-exits/http-exits.yaml
+++ b/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cloudflared-tunnel-exits/http-exits.yaml
@@ -102,7 +102,7 @@ spec:
 
           # Argo Eventsのリバースプロキシ。
           - name: argo-events-reverse-proxy
-            external-hostname: argo-workflows-reverse-proxy.onp-k8s.admin.seichi.click
+            external-hostname: argo-workflows-webhook.onp-k8s.admin.seichi.click
             internal-authority: "argo-events-reverse-proxy.argocd:80"
 
   template:
diff --git a/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cluster-wide-apps/app-of-other-apps/argo-events-reverse-proxy.yaml b/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cluster-wide-apps/app-of-other-apps/argo-events-reverse-proxy.yaml
index c45acc416..e26982375 100644
--- a/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cluster-wide-apps/app-of-other-apps/argo-events-reverse-proxy.yaml
+++ b/seichi-onp-k8s/manifests/seichi-kubernetes/apps/cluster-wide-apps/app-of-other-apps/argo-events-reverse-proxy.yaml
@@ -1,3 +1,5 @@
+# 外部から Argo Workflows を発火するためには Cloudflared を使えば機能的には問題がないが、
+# 任意のクライアントから GET を受け付けると面倒なので、POST だけに限定するためのリバースプロキシを挟む。
 apiVersion: v1
 kind: Deployment
 metadata:
@@ -23,11 +25,10 @@ metadata:
   namespace: argocd
 data:
   nginx.conf: |
-    events {
-    }
     http {
       server {
         listen 80;
+        server_name argo-workflows-webhook.onp-k8s.admin.seichi.click;
         location / {
           if ($request_method !~ ^(POST)$ ) {
             return 405;