diff --git a/packages/core/platform/tests/apps_load_balancer_class_wiring_test.yaml b/packages/core/platform/tests/apps_load_balancer_class_wiring_test.yaml
new file mode 100644
index 000000000..34d04c8c1
--- /dev/null
+++ b/packages/core/platform/tests/apps_load_balancer_class_wiring_test.yaml
@@ -0,0 +1,29 @@
+suite: apps.yaml publishing.loadBalancerClass → _cluster wiring
+templates:
+  - templates/apps.yaml
+
+release:
+  name: cozy-platform
+  namespace: cozy-system
+
+# publishing.loadBalancerClass selects which LoadBalancer controller handles the
+# host ingress Service. It reaches the host ingress-nginx through
+# _cluster.load-balancer-class in the cozystack-values Secret (the same path
+# expose-external-ips and proxy-protocol travel). These assertions pin that the
+# value lands in the Secret; without them the host ingress would silently never
+# see the configured loadBalancerClass.
+
+tests:
+  - it: writes an empty load-balancer-class by default
+    asserts:
+      - matchRegex:
+          path: stringData["values.yaml"]
+          pattern: '(?m)^\s*load-balancer-class:\s*""'
+
+  - it: writes the load-balancer-class when publishing.loadBalancerClass is set
+    set:
+      publishing.loadBalancerClass: metallb.io/metallb
+    asserts:
+      - matchRegex:
+          path: stringData["values.yaml"]
+          pattern: '(?m)^\s*load-balancer-class:\s*"metallb\.io/metallb"'
diff --git a/packages/extra/ingress/templates/nginx-ingress.yaml b/packages/extra/ingress/templates/nginx-ingress.yaml
index b09ec2ea2..1276b9c4a 100644
--- a/packages/extra/ingress/templates/nginx-ingress.yaml
+++ b/packages/extra/ingress/templates/nginx-ingress.yaml
@@ -82,8 +82,12 @@ spec:
           {{- else }}
           type: LoadBalancer
           externalTrafficPolicy: Local
-          {{- with $loadBalancerClass }}
-          loadBalancerClass: {{ . }}
+          {{- /* loadBalancerClass is a host-publishing setting: apply it only to
+                 the external-facing ingress (the namespace named by expose-ingress),
+                 host-scoped like expose-external-ips and proxy-protocol above.
+                 Tenant ingress Services keep the cluster's default LB controller. */}}
+          {{- if and $loadBalancerClass (eq $exposeIngress .Release.Namespace) }}
+          loadBalancerClass: {{ $loadBalancerClass }}
           {{- end }}
           {{- end }}
         {{- if or .Values.whitelist .Values.cloudflareProxy $proxyProtocol }}
diff --git a/packages/extra/ingress/tests/load_balancer_class_test.yaml b/packages/extra/ingress/tests/load_balancer_class_test.yaml
new file mode 100644
index 000000000..0dd92ddb7
--- /dev/null
+++ b/packages/extra/ingress/tests/load_balancer_class_test.yaml
@@ -0,0 +1,69 @@
+suite: ingress loadBalancerClass wiring
+templates:
+  - templates/nginx-ingress.yaml
+release:
+  name: ingress
+
+# publishing.loadBalancerClass is a host-publishing setting carried in
+# _cluster.load-balancer-class. It must land on the external-facing (host)
+# ingress Service only — host-scoped like expose-external-ips and
+# proxy-protocol. These assertions pin that scope: a tenant ingress must NOT
+# inherit the host's loadBalancerClass, or its Service would be claimed by an
+# LB controller the tenant never asked for.
+tests:
+  - it: sets loadBalancerClass on the host ingress LoadBalancer Service
+    set:
+      _cluster:
+        expose-ingress: tenant-root
+        load-balancer-class: metallb.io/metallb
+    release:
+      namespace: tenant-root
+    asserts:
+      - equal:
+          path: spec.values.ingress-nginx.controller.service.type
+          value: LoadBalancer
+      - equal:
+          path: spec.values.ingress-nginx.controller.service.loadBalancerClass
+          value: metallb.io/metallb
+
+  - it: does not leak the host loadBalancerClass onto a tenant ingress
+    set:
+      _cluster:
+        expose-ingress: tenant-root
+        load-balancer-class: metallb.io/metallb
+    release:
+      namespace: tenant-foo
+    asserts:
+      - equal:
+          path: spec.values.ingress-nginx.controller.service.type
+          value: LoadBalancer
+      - notExists:
+          path: spec.values.ingress-nginx.controller.service.loadBalancerClass
+
+  - it: keeps the externalIPs path untouched by loadBalancerClass
+    set:
+      _cluster:
+        expose-ingress: tenant-root
+        expose-external-ips: 203.0.113.10
+        load-balancer-class: metallb.io/metallb
+    release:
+      namespace: tenant-root
+    asserts:
+      - equal:
+          path: spec.values.ingress-nginx.controller.service.type
+          value: ClusterIP
+      - notExists:
+          path: spec.values.ingress-nginx.controller.service.loadBalancerClass
+
+  - it: omits loadBalancerClass on the host ingress when none is configured
+    set:
+      _cluster:
+        expose-ingress: tenant-root
+    release:
+      namespace: tenant-root
+    asserts:
+      - equal:
+          path: spec.values.ingress-nginx.controller.service.type
+          value: LoadBalancer
+      - notExists:
+          path: spec.values.ingress-nginx.controller.service.loadBalancerClass