diff --git a/ci/cyberchef/test-values.yaml b/ci/cyberchef/test-values.yaml
index 64aa16e..354205a 100644
--- a/ci/cyberchef/test-values.yaml
+++ b/ci/cyberchef/test-values.yaml
@@ -1,5 +1,6 @@
-# cyberchef: stateless, no secrets. Only the ingress host is required
-# (clusterIssuer already has a default). The Ingress just has to apply -
-# there is no ingress-nginx/cert-manager in the CI cluster.
+# cyberchef: stateless, no secrets. Only the required ingress values are set.
+# The Ingress just has to apply - there is no ingress-nginx/cert-manager in
+# the CI cluster.
 ingress:
   domain: cyberchef.ci.local
+  clusterIssuer: ci
diff --git a/ci/urlaubsverwaltung/test-values.yaml b/ci/urlaubsverwaltung/test-values.yaml
index 25a6351..8b2dd38 100644
--- a/ci/urlaubsverwaltung/test-values.yaml
+++ b/ci/urlaubsverwaltung/test-values.yaml
@@ -4,3 +4,6 @@ secrets:
 
 ingress:
   domain: uv.ci.local
+  # clusterIssuer is strictly required (no default); the Ingress just has to
+  # apply - there is no cert-manager in the CI cluster.
+  clusterIssuer: ci
diff --git a/cyberchef/Chart.yaml b/cyberchef/Chart.yaml
index 59bc61a..ad80563 100644
--- a/cyberchef/Chart.yaml
+++ b/cyberchef/Chart.yaml
@@ -5,7 +5,7 @@ icon: https://raw.githubusercontent.com/gchq/CyberChef/master/src/web/static/ima
 
 type: application
 
-version: 5.2.0+up11.4.0
+version: 6.0.0+up11.4.0
 appVersion: "11.4.0"
 
 maintainers:
diff --git a/cyberchef/values.yaml b/cyberchef/values.yaml
index 0796648..c891758 100644
--- a/cyberchef/values.yaml
+++ b/cyberchef/values.yaml
@@ -60,7 +60,7 @@ cyberchef:
 
 ingress:
   enabled: true
-  clusterIssuer: letsencrypt
+  clusterIssuer: null
   domain: null
   className: nginx
   # Extra annotations for the Ingress; merged with the cert-manager
diff --git a/urlaubsverwaltung/Chart.yaml b/urlaubsverwaltung/Chart.yaml
index 6220576..98c02f9 100644
--- a/urlaubsverwaltung/Chart.yaml
+++ b/urlaubsverwaltung/Chart.yaml
@@ -4,5 +4,5 @@ description: A Helm chart to deploy urlaubsverwaltung on Kubernetes
 icon: https://raw.githubusercontent.com/urlaubsverwaltung/urlaubsverwaltung/main/src/main/resources/static/favicons/apple-touch-icon.png
 type: application
 
-version: 5.0.0+up6.7.0
+version: 6.0.0+up6.7.0
 appVersion: 6.7.0
diff --git a/urlaubsverwaltung/values.yaml b/urlaubsverwaltung/values.yaml
index 76a5cc4..f6ca655 100644
--- a/urlaubsverwaltung/values.yaml
+++ b/urlaubsverwaltung/values.yaml
@@ -10,7 +10,7 @@ secrets:
 
 ingress:
   enabled: true
-  clusterIssuer: "letsencrypt-issuer"
+  clusterIssuer: null
   domain: null
   className: nginx
   # Extra annotations for the Ingress; merged with the cert-manager