diff --git a/pkg/apis/admissionregistration/v1/defaults_test.go b/pkg/apis/admissionregistration/v1/defaults_test.go
new file mode 100644
index 00000000000..41979c9eee7
--- /dev/null
+++ b/pkg/apis/admissionregistration/v1/defaults_test.go
@@ -0,0 +1,134 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1_test
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	v1 "k8s.io/api/admissionregistration/v1"
+	apiequality "k8s.io/apimachinery/pkg/api/equality"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	_ "k8s.io/kubernetes/pkg/apis/admissionregistration/install"
+	utilpointer "k8s.io/utils/pointer"
+)
+
+func TestDefaultAdmissionWebhook(t *testing.T) {
+	fail := v1.Fail
+	equivalent := v1.Equivalent
+	never := v1.NeverReinvocationPolicy
+	ten := int32(10)
+	allScopes := v1.AllScopes
+
+	tests := []struct {
+		name     string
+		original runtime.Object
+		expected runtime.Object
+	}{
+		{
+			name: "ValidatingWebhookConfiguration",
+			original: &v1.ValidatingWebhookConfiguration{
+				Webhooks: []v1.ValidatingWebhook{{}},
+			},
+			expected: &v1.ValidatingWebhookConfiguration{
+				Webhooks: []v1.ValidatingWebhook{{
+					FailurePolicy:     &fail,
+					MatchPolicy:       &equivalent,
+					TimeoutSeconds:    &ten,
+					NamespaceSelector: &metav1.LabelSelector{},
+					ObjectSelector:    &metav1.LabelSelector{},
+				}},
+			},
+		},
+		{
+			name: "MutatingWebhookConfiguration",
+			original: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{}},
+			},
+			expected: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{
+					FailurePolicy:      &fail,
+					MatchPolicy:        &equivalent,
+					ReinvocationPolicy: &never,
+					TimeoutSeconds:     &ten,
+					NamespaceSelector:  &metav1.LabelSelector{},
+					ObjectSelector:     &metav1.LabelSelector{},
+				}},
+			},
+		},
+		{
+			name: "scope=*",
+			original: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{
+					Rules: []v1.RuleWithOperations{{}},
+				}},
+			},
+			expected: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{
+					Rules: []v1.RuleWithOperations{{Rule: v1.Rule{
+						Scope: &allScopes, // defaulted
+					}}},
+					FailurePolicy:      &fail,
+					MatchPolicy:        &equivalent,
+					ReinvocationPolicy: &never,
+					TimeoutSeconds:     &ten,
+					NamespaceSelector:  &metav1.LabelSelector{},
+					ObjectSelector:     &metav1.LabelSelector{},
+				}},
+			},
+		},
+		{
+			name: "port=443",
+			original: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{
+					ClientConfig: v1.WebhookClientConfig{
+						Service: &v1.ServiceReference{},
+					},
+				}},
+			},
+			expected: &v1.MutatingWebhookConfiguration{
+				Webhooks: []v1.MutatingWebhook{{
+					ClientConfig: v1.WebhookClientConfig{
+						Service: &v1.ServiceReference{
+							Port: utilpointer.Int32Ptr(443), // defaulted
+						},
+					},
+					FailurePolicy:      &fail,
+					MatchPolicy:        &equivalent,
+					ReinvocationPolicy: &never,
+					TimeoutSeconds:     &ten,
+					NamespaceSelector:  &metav1.LabelSelector{},
+					ObjectSelector:     &metav1.LabelSelector{},
+				}},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			original := test.original
+			expected := test.expected
+			legacyscheme.Scheme.Default(original)
+			if !apiequality.Semantic.DeepEqual(original, expected) {
+				t.Error(cmp.Diff(expected, original))
+			}
+		})
+	}
+}
diff --git a/pkg/apis/admissionregistration/v1beta1/defaults_test.go b/pkg/apis/admissionregistration/v1beta1/defaults_test.go
new file mode 100644
index 00000000000..cc26c2c5bb9
--- /dev/null
+++ b/pkg/apis/admissionregistration/v1beta1/defaults_test.go
@@ -0,0 +1,143 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1beta1_test
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+
+	v1beta1 "k8s.io/api/admissionregistration/v1beta1"
+	apiequality "k8s.io/apimachinery/pkg/api/equality"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/kubernetes/pkg/api/legacyscheme"
+	_ "k8s.io/kubernetes/pkg/apis/admissionregistration/install"
+	utilpointer "k8s.io/utils/pointer"
+)
+
+func TestDefaultAdmissionWebhook(t *testing.T) {
+	ignore := v1beta1.Ignore
+	exact := v1beta1.Exact
+	never := v1beta1.NeverReinvocationPolicy
+	thirty := int32(30)
+	allScopes := v1beta1.AllScopes
+	unknown := v1beta1.SideEffectClassUnknown
+
+	tests := []struct {
+		name     string
+		original runtime.Object
+		expected runtime.Object
+	}{
+		{
+			name: "ValidatingWebhookConfiguration",
+			original: &v1beta1.ValidatingWebhookConfiguration{
+				Webhooks: []v1beta1.ValidatingWebhook{{}},
+			},
+			expected: &v1beta1.ValidatingWebhookConfiguration{
+				Webhooks: []v1beta1.ValidatingWebhook{{
+					FailurePolicy:           &ignore,
+					MatchPolicy:             &exact,
+					TimeoutSeconds:          &thirty,
+					NamespaceSelector:       &metav1.LabelSelector{},
+					ObjectSelector:          &metav1.LabelSelector{},
+					SideEffects:             &unknown,
+					AdmissionReviewVersions: []string{"v1beta1"},
+				}},
+			},
+		},
+		{
+			name: "MutatingWebhookConfiguration",
+			original: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{}},
+			},
+			expected: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{
+					FailurePolicy:           &ignore,
+					MatchPolicy:             &exact,
+					ReinvocationPolicy:      &never,
+					TimeoutSeconds:          &thirty,
+					NamespaceSelector:       &metav1.LabelSelector{},
+					ObjectSelector:          &metav1.LabelSelector{},
+					SideEffects:             &unknown,
+					AdmissionReviewVersions: []string{"v1beta1"},
+				}},
+			},
+		},
+		{
+			name: "scope=*",
+			original: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{
+					Rules: []v1beta1.RuleWithOperations{{}},
+				}},
+			},
+			expected: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{
+					Rules: []v1beta1.RuleWithOperations{{Rule: v1beta1.Rule{
+						Scope: &allScopes, // defaulted
+					}}},
+					FailurePolicy:           &ignore,
+					MatchPolicy:             &exact,
+					ReinvocationPolicy:      &never,
+					TimeoutSeconds:          &thirty,
+					NamespaceSelector:       &metav1.LabelSelector{},
+					ObjectSelector:          &metav1.LabelSelector{},
+					SideEffects:             &unknown,
+					AdmissionReviewVersions: []string{"v1beta1"},
+				}},
+			},
+		},
+		{
+			name: "port=443",
+			original: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{
+					ClientConfig: v1beta1.WebhookClientConfig{
+						Service: &v1beta1.ServiceReference{},
+					},
+				}},
+			},
+			expected: &v1beta1.MutatingWebhookConfiguration{
+				Webhooks: []v1beta1.MutatingWebhook{{
+					ClientConfig: v1beta1.WebhookClientConfig{
+						Service: &v1beta1.ServiceReference{
+							Port: utilpointer.Int32Ptr(443), // defaulted
+						},
+					},
+					FailurePolicy:           &ignore,
+					MatchPolicy:             &exact,
+					ReinvocationPolicy:      &never,
+					TimeoutSeconds:          &thirty,
+					NamespaceSelector:       &metav1.LabelSelector{},
+					ObjectSelector:          &metav1.LabelSelector{},
+					SideEffects:             &unknown,
+					AdmissionReviewVersions: []string{"v1beta1"},
+				}},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			original := test.original
+			expected := test.expected
+			legacyscheme.Scheme.Default(original)
+			if !apiequality.Semantic.DeepEqual(original, expected) {
+				t.Error(cmp.Diff(expected, original))
+			}
+		})
+	}
+}