diff --git a/api/krusty/validatingwebhook_test.go b/api/krusty/validatingwebhook_test.go
new file mode 100644
index 000000000..a57889f46
--- /dev/null
+++ b/api/krusty/validatingwebhook_test.go
@@ -0,0 +1,136 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package krusty_test
+
+import (
+	"testing"
+
+	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
+)
+
+func TestValidatingWebhookCombinedNamespaces(t *testing.T) {
+  th := kusttest_test.MakeHarness(t)
+  th.WriteK("base", `
+resources:
+- service.yaml
+- validatingwebhook.yaml
+`)
+  th.WriteF("base/service.yaml", `
+apiVersion: v1
+kind: Service
+metadata:
+  name: admission
+  namespace: base-namespace
+spec:
+  type: ClusterIP
+  ports:
+    - name: https-webhook
+      port: 443
+      targetPort: webhook
+`)
+    th.WriteF("base/validatingwebhook.yaml", `
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingWebhookConfiguration
+metadata:
+  name: validatingwebhook
+webhooks:
+  - name: validate
+    matchPolicy: Equivalent
+    rules:
+      - apiGroups:
+          - networking.k8s.io
+        apiVersions:
+          - v1beta1
+        operations:
+          - CREATE
+          - UPDATE
+        resources:
+          - ingresses
+    failurePolicy: Fail
+    sideEffects: None
+    admissionReviewVersions:
+      - v1
+      - v1beta1
+    clientConfig:
+      service:
+        namespace: base-namespace
+        name: admission
+        path: /networking/v1beta1/ingresses
+`)
+  th.WriteK("overlay", `
+namespace: merge-namespace
+resources:
+- ../base
+patchesStrategicMerge:
+- validatingwebhookdelete.yaml
+`)
+    th.WriteF("overlay/validatingwebhookdelete.yaml", `
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingWebhookConfiguration
+metadata:
+  name: validatingwebhook
+$patch: delete
+`)
+	th.WriteK("combined", `
+resources:
+- ../base
+- ../overlay
+`)
+	m := th.Run("combined", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+kind: Service
+metadata:
+  name: admission
+  namespace: base-namespace
+spec:
+  ports:
+  - name: https-webhook
+    port: 443
+    targetPort: webhook
+  type: ClusterIP
+---
+apiVersion: admissionregistration.k8s.io/v1
+kind: ValidatingWebhookConfiguration
+metadata:
+  name: validatingwebhook
+webhooks:
+- admissionReviewVersions:
+  - v1
+  - v1beta1
+  clientConfig:
+    service:
+      name: admission
+      namespace: base-namespace
+      path: /networking/v1beta1/ingresses
+  failurePolicy: Fail
+  matchPolicy: Equivalent
+  name: validate
+  rules:
+  - apiGroups:
+    - networking.k8s.io
+    apiVersions:
+    - v1beta1
+    operations:
+    - CREATE
+    - UPDATE
+    resources:
+    - ingresses
+  sideEffects: None
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: admission
+  namespace: merge-namespace
+spec:
+  ports:
+  - name: https-webhook
+    port: 443
+    targetPort: webhook
+  type: ClusterIP
+`)
+}
+
+