diff --git a/cmd/k8s-operator/sts_test.go b/cmd/k8s-operator/sts_test.go
index ea28e77a1..bb7089deb 100644
--- a/cmd/k8s-operator/sts_test.go
+++ b/cmd/k8s-operator/sts_test.go
@@ -71,11 +71,11 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 					SecurityContext: &corev1.PodSecurityContext{
 						RunAsUser: ptr.To(int64(0)),
 					},
-					ImagePullSecrets: []corev1.LocalObjectReference{{Name: "docker-creds"}},
-					NodeName:         "some-node",
-					NodeSelector:     map[string]string{"beta.kubernetes.io/os": "linux"},
-					Affinity:         &corev1.Affinity{NodeAffinity: &corev1.NodeAffinity{RequiredDuringSchedulingIgnoredDuringExecution: &corev1.NodeSelector{}}},
-					Tolerations:      []corev1.Toleration{{Key: "", Operator: "Exists"}},
+					ImagePullSecrets:  []corev1.LocalObjectReference{{Name: "docker-creds"}},
+					NodeName:          "some-node",
+					NodeSelector:      map[string]string{"beta.kubernetes.io/os": "linux"},
+					Affinity:          &corev1.Affinity{NodeAffinity: &corev1.NodeAffinity{RequiredDuringSchedulingIgnoredDuringExecution: &corev1.NodeSelector{}}},
+					Tolerations:       []corev1.Toleration{{Key: "", Operator: "Exists"}},
 					PriorityClassName: "high-priority",
 					TopologySpreadConstraints: []corev1.TopologySpreadConstraint{
 						{
@@ -310,6 +310,30 @@ func Test_applyProxyClassToStatefulSet(t *testing.T) {
 		t.Errorf("Unexpected result applying ProxyClass with metrics enabled to a StatefulSet (-got +want):\n%s", diff)
 	}
 
+	// 7b. Enable metrics with custom port name.
+	customPortNamePC := &tsapi.ProxyClass{
+		Spec: tsapi.ProxyClassSpec{
+			Metrics: &tsapi.Metrics{Enable: true, PortName: "ts-metrics"},
+			StatefulSet: &tsapi.StatefulSet{
+				Pod: &tsapi.Pod{
+					TailscaleContainer: &tsapi.Container{
+						Debug: &tsapi.Debug{Enable: false},
+					},
+				},
+			},
+		},
+	}
+	wantSS = nonUserspaceProxySS.DeepCopy()
+	wantSS.Spec.Template.Spec.Containers[0].Env = append(wantSS.Spec.Template.Spec.Containers[0].Env,
+		corev1.EnvVar{Name: "TS_LOCAL_ADDR_PORT", Value: "$(POD_IP):9002"},
+		corev1.EnvVar{Name: "TS_ENABLE_METRICS", Value: "true"},
+	)
+	wantSS.Spec.Template.Spec.Containers[0].Ports = []corev1.ContainerPort{{Name: "ts-metrics", Protocol: "TCP", ContainerPort: 9002}}
+	gotSS = applyProxyClassToStatefulSet(customPortNamePC, nonUserspaceProxySS.DeepCopy(), new(tailscaleSTSConfig), zl.Sugar())
+	if diff := cmp.Diff(gotSS, wantSS); diff != "" {
+		t.Errorf("Unexpected result applying ProxyClass with custom metrics port name to a StatefulSet (-got +want):\n%s", diff)
+	}
+
 	// 8. A Kubernetes API proxy with letsencrypt staging enabled
 	gotSS = applyProxyClassToStatefulSet(proxyClassAllOpts, nonUserspaceProxySS.DeepCopy(), &tailscaleSTSConfig{proxyType: string(tsapi.ProxyGroupTypeKubernetesAPIServer)}, zl.Sugar())
 	verifyEnvVar(t, gotSS, "TS_DEBUG_ACME_DIRECTORY_URL", letsEncryptStagingEndpoint)