diff --git a/argocd/apps/openproject/values-openproject.yaml b/argocd/apps/openproject/values-openproject.yaml
index f16d54b..0929833 100644
--- a/argocd/apps/openproject/values-openproject.yaml
+++ b/argocd/apps/openproject/values-openproject.yaml
@@ -19,7 +19,7 @@ spec:
             kubernetes.io/ingress.class: traefik
             traefik.ingress.kubernetes.io/router.entrypoints: websecure
             traefik.ingress.kubernetes.io/router.tls: "true"
-            cert-manager.io/cluster-issuer: lets-encrypt
+            cert-manager.io/cluster-issuer: lets-encrypt-staging
           host: "openproject.innovation-hub-niedersachsen.de"
           path: /
           pathType: "Prefix"