diff --git a/staging/src/k8s.io/api/admissionregistration/v1alpha1/types.go b/staging/src/k8s.io/api/admissionregistration/v1alpha1/types.go
index 575456c8386..bd6b17e1588 100644
--- a/staging/src/k8s.io/api/admissionregistration/v1alpha1/types.go
+++ b/staging/src/k8s.io/api/admissionregistration/v1alpha1/types.go
@@ -226,7 +226,7 @@ type ValidatingAdmissionPolicySpec struct {
 	// +listType=map
 	// +listMapKey=name
 	// +optional
-	Variables []Variable `json:"variables" patchStrategy:"merge" patchMergeKey:"name" protobuf:"bytes,7,rep,name=variables"`
+	Variables []Variable `json:"variables,omitempty" patchStrategy:"merge" patchMergeKey:"name" protobuf:"bytes,7,rep,name=variables"`
 }
 
 type MatchCondition v1.MatchCondition
diff --git a/staging/src/k8s.io/api/admissionregistration/v1beta1/types.go b/staging/src/k8s.io/api/admissionregistration/v1beta1/types.go
index c199702fbd0..12c680dc972 100644
--- a/staging/src/k8s.io/api/admissionregistration/v1beta1/types.go
+++ b/staging/src/k8s.io/api/admissionregistration/v1beta1/types.go
@@ -242,7 +242,7 @@ type ValidatingAdmissionPolicySpec struct {
 	// +listType=map
 	// +listMapKey=name
 	// +optional
-	Variables []Variable `json:"variables" patchStrategy:"merge" patchMergeKey:"name" protobuf:"bytes,7,rep,name=variables"`
+	Variables []Variable `json:"variables,omitempty" patchStrategy:"merge" patchMergeKey:"name" protobuf:"bytes,7,rep,name=variables"`
 }
 
 // ParamKind is a tuple of Group Kind and Version.
diff --git a/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.json b/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.json
deleted file mode 100644
index d61b666f317..00000000000
--- a/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.json
+++ /dev/null
@@ -1,166 +0,0 @@
-{
-  "kind": "ValidatingAdmissionPolicy",
-  "apiVersion": "admissionregistration.k8s.io/v1alpha1",
-  "metadata": {
-    "name": "nameValue",
-    "generateName": "generateNameValue",
-    "namespace": "namespaceValue",
-    "selfLink": "selfLinkValue",
-    "uid": "uidValue",
-    "resourceVersion": "resourceVersionValue",
-    "generation": 7,
-    "creationTimestamp": "2008-01-01T01:01:01Z",
-    "deletionTimestamp": "2009-01-01T01:01:01Z",
-    "deletionGracePeriodSeconds": 10,
-    "labels": {
-      "labelsKey": "labelsValue"
-    },
-    "annotations": {
-      "annotationsKey": "annotationsValue"
-    },
-    "ownerReferences": [
-      {
-        "apiVersion": "apiVersionValue",
-        "kind": "kindValue",
-        "name": "nameValue",
-        "uid": "uidValue",
-        "controller": true,
-        "blockOwnerDeletion": true
-      }
-    ],
-    "finalizers": [
-      "finalizersValue"
-    ],
-    "managedFields": [
-      {
-        "manager": "managerValue",
-        "operation": "operationValue",
-        "apiVersion": "apiVersionValue",
-        "time": "2004-01-01T01:01:01Z",
-        "fieldsType": "fieldsTypeValue",
-        "fieldsV1": {},
-        "subresource": "subresourceValue"
-      }
-    ]
-  },
-  "spec": {
-    "paramKind": {
-      "apiVersion": "apiVersionValue",
-      "kind": "kindValue"
-    },
-    "matchConstraints": {
-      "namespaceSelector": {
-        "matchLabels": {
-          "matchLabelsKey": "matchLabelsValue"
-        },
-        "matchExpressions": [
-          {
-            "key": "keyValue",
-            "operator": "operatorValue",
-            "values": [
-              "valuesValue"
-            ]
-          }
-        ]
-      },
-      "objectSelector": {
-        "matchLabels": {
-          "matchLabelsKey": "matchLabelsValue"
-        },
-        "matchExpressions": [
-          {
-            "key": "keyValue",
-            "operator": "operatorValue",
-            "values": [
-              "valuesValue"
-            ]
-          }
-        ]
-      },
-      "resourceRules": [
-        {
-          "resourceNames": [
-            "resourceNamesValue"
-          ],
-          "operations": [
-            "operationsValue"
-          ],
-          "apiGroups": [
-            "apiGroupsValue"
-          ],
-          "apiVersions": [
-            "apiVersionsValue"
-          ],
-          "resources": [
-            "resourcesValue"
-          ],
-          "scope": "scopeValue"
-        }
-      ],
-      "excludeResourceRules": [
-        {
-          "resourceNames": [
-            "resourceNamesValue"
-          ],
-          "operations": [
-            "operationsValue"
-          ],
-          "apiGroups": [
-            "apiGroupsValue"
-          ],
-          "apiVersions": [
-            "apiVersionsValue"
-          ],
-          "resources": [
-            "resourcesValue"
-          ],
-          "scope": "scopeValue"
-        }
-      ],
-      "matchPolicy": "matchPolicyValue"
-    },
-    "validations": [
-      {
-        "expression": "expressionValue",
-        "message": "messageValue",
-        "reason": "reasonValue",
-        "messageExpression": "messageExpressionValue"
-      }
-    ],
-    "failurePolicy": "failurePolicyValue",
-    "auditAnnotations": [
-      {
-        "key": "keyValue",
-        "valueExpression": "valueExpressionValue"
-      }
-    ],
-    "matchConditions": [
-      {
-        "name": "nameValue",
-        "expression": "expressionValue"
-      }
-    ],
-    "variables": null
-  },
-  "status": {
-    "observedGeneration": 1,
-    "typeChecking": {
-      "expressionWarnings": [
-        {
-          "fieldRef": "fieldRefValue",
-          "warning": "warningValue"
-        }
-      ]
-    },
-    "conditions": [
-      {
-        "type": "typeValue",
-        "status": "statusValue",
-        "observedGeneration": 3,
-        "lastTransitionTime": "2004-01-01T01:01:01Z",
-        "reason": "reasonValue",
-        "message": "messageValue"
-      }
-    ]
-  }
-}
\ No newline at end of file
diff --git a/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.yaml b/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.yaml
deleted file mode 100644
index 1cc7e0a8f32..00000000000
--- a/staging/src/k8s.io/api/testdata/v1.27.0/admissionregistration.k8s.io.v1alpha1.ValidatingAdmissionPolicy.after_roundtrip.yaml
+++ /dev/null
@@ -1,106 +0,0 @@
-apiVersion: admissionregistration.k8s.io/v1alpha1
-kind: ValidatingAdmissionPolicy
-metadata:
-  annotations:
-    annotationsKey: annotationsValue
-  creationTimestamp: "2008-01-01T01:01:01Z"
-  deletionGracePeriodSeconds: 10
-  deletionTimestamp: "2009-01-01T01:01:01Z"
-  finalizers:
-  - finalizersValue
-  generateName: generateNameValue
-  generation: 7
-  labels:
-    labelsKey: labelsValue
-  managedFields:
-  - apiVersion: apiVersionValue
-    fieldsType: fieldsTypeValue
-    fieldsV1: {}
-    manager: managerValue
-    operation: operationValue
-    subresource: subresourceValue
-    time: "2004-01-01T01:01:01Z"
-  name: nameValue
-  namespace: namespaceValue
-  ownerReferences:
-  - apiVersion: apiVersionValue
-    blockOwnerDeletion: true
-    controller: true
-    kind: kindValue
-    name: nameValue
-    uid: uidValue
-  resourceVersion: resourceVersionValue
-  selfLink: selfLinkValue
-  uid: uidValue
-spec:
-  auditAnnotations:
-  - key: keyValue
-    valueExpression: valueExpressionValue
-  failurePolicy: failurePolicyValue
-  matchConditions:
-  - expression: expressionValue
-    name: nameValue
-  matchConstraints:
-    excludeResourceRules:
-    - apiGroups:
-      - apiGroupsValue
-      apiVersions:
-      - apiVersionsValue
-      operations:
-      - operationsValue
-      resourceNames:
-      - resourceNamesValue
-      resources:
-      - resourcesValue
-      scope: scopeValue
-    matchPolicy: matchPolicyValue
-    namespaceSelector:
-      matchExpressions:
-      - key: keyValue
-        operator: operatorValue
-        values:
-        - valuesValue
-      matchLabels:
-        matchLabelsKey: matchLabelsValue
-    objectSelector:
-      matchExpressions:
-      - key: keyValue
-        operator: operatorValue
-        values:
-        - valuesValue
-      matchLabels:
-        matchLabelsKey: matchLabelsValue
-    resourceRules:
-    - apiGroups:
-      - apiGroupsValue
-      apiVersions:
-      - apiVersionsValue
-      operations:
-      - operationsValue
-      resourceNames:
-      - resourceNamesValue
-      resources:
-      - resourcesValue
-      scope: scopeValue
-  paramKind:
-    apiVersion: apiVersionValue
-    kind: kindValue
-  validations:
-  - expression: expressionValue
-    message: messageValue
-    messageExpression: messageExpressionValue
-    reason: reasonValue
-  variables: null
-status:
-  conditions:
-  - lastTransitionTime: "2004-01-01T01:01:01Z"
-    message: messageValue
-    observedGeneration: 3
-    reason: reasonValue
-    status: statusValue
-    type: typeValue
-  observedGeneration: 1
-  typeChecking:
-    expressionWarnings:
-    - fieldRef: fieldRefValue
-      warning: warningValue