diff --git a/api/openapi-spec/swagger.json b/api/openapi-spec/swagger.json
index a90636d11c6..7648d793986 100644
--- a/api/openapi-spec/swagger.json
+++ b/api/openapi-spec/swagger.json
@@ -19125,7 +19125,15 @@
           "description": "Gang specifies that the pods in this group should be scheduled using all-or-nothing semantics."
         }
       },
-      "type": "object"
+      "type": "object",
+      "x-kubernetes-unions": [
+        {
+          "fields-to-discriminateBy": {
+            "basic": "Basic",
+            "gang": "Gang"
+          }
+        }
+      ]
     },
     "io.k8s.api.scheduling.v1alpha1.TypedLocalObjectReference": {
       "description": "TypedLocalObjectReference allows to reference typed object inside the same namespace.",
diff --git a/api/openapi-spec/v3/apis__scheduling.k8s.io__v1alpha1_openapi.json b/api/openapi-spec/v3/apis__scheduling.k8s.io__v1alpha1_openapi.json
index 897abf9c1b1..7a38f8d6559 100644
--- a/api/openapi-spec/v3/apis__scheduling.k8s.io__v1alpha1_openapi.json
+++ b/api/openapi-spec/v3/apis__scheduling.k8s.io__v1alpha1_openapi.json
@@ -64,7 +64,15 @@
             "description": "Gang specifies that the pods in this group should be scheduled using all-or-nothing semantics."
           }
         },
-        "type": "object"
+        "type": "object",
+        "x-kubernetes-unions": [
+          {
+            "fields-to-discriminateBy": {
+              "basic": "Basic",
+              "gang": "Gang"
+            }
+          }
+        ]
       },
       "io.k8s.api.scheduling.v1alpha1.TypedLocalObjectReference": {
         "description": "TypedLocalObjectReference allows to reference typed object inside the same namespace.",
diff --git a/pkg/generated/openapi/zz_generated.openapi.go b/pkg/generated/openapi/zz_generated.openapi.go
index 535aba16981..805409848bf 100644
--- a/pkg/generated/openapi/zz_generated.openapi.go
+++ b/pkg/generated/openapi/zz_generated.openapi.go
@@ -53351,6 +53351,18 @@ func schema_k8sio_api_scheduling_v1alpha1_PodGroupPolicy(ref common.ReferenceCal
 					},
 				},
 			},
+			VendorExtensible: spec.VendorExtensible{
+				Extensions: spec.Extensions{
+					"x-kubernetes-unions": []interface{}{
+						map[string]interface{}{
+							"fields-to-discriminateBy": map[string]interface{}{
+								"basic": "Basic",
+								"gang":  "Gang",
+							},
+						},
+					},
+				},
+			},
 		},
 		Dependencies: []string{
 			schedulingv1alpha1.BasicSchedulingPolicy{}.OpenAPIModelName(), schedulingv1alpha1.GangSchedulingPolicy{}.OpenAPIModelName()},
diff --git a/staging/src/k8s.io/api/scheduling/v1alpha1/generated.proto b/staging/src/k8s.io/api/scheduling/v1alpha1/generated.proto
index f89ebcac632..e0dc025e1b2 100644
--- a/staging/src/k8s.io/api/scheduling/v1alpha1/generated.proto
+++ b/staging/src/k8s.io/api/scheduling/v1alpha1/generated.proto
@@ -63,6 +63,7 @@ message PodGroup {
 }
 
 // PodGroupPolicy defines the scheduling configuration for a PodGroup.
+// +union
 message PodGroupPolicy {
   // Basic specifies that the pods in this group should be scheduled using
   // standard Kubernetes scheduling behavior.
diff --git a/staging/src/k8s.io/api/scheduling/v1alpha1/types.go b/staging/src/k8s.io/api/scheduling/v1alpha1/types.go
index 3724c279007..ed4228a82af 100644
--- a/staging/src/k8s.io/api/scheduling/v1alpha1/types.go
+++ b/staging/src/k8s.io/api/scheduling/v1alpha1/types.go
@@ -181,6 +181,7 @@ type PodGroup struct {
 }
 
 // PodGroupPolicy defines the scheduling configuration for a PodGroup.
+// +union
 type PodGroupPolicy struct {
 	// Basic specifies that the pods in this group should be scheduled using
 	// standard Kubernetes scheduling behavior.
diff --git a/staging/src/k8s.io/client-go/applyconfigurations/internal/internal.go b/staging/src/k8s.io/client-go/applyconfigurations/internal/internal.go
index bf4f28b9627..368e4df3a47 100644
--- a/staging/src/k8s.io/client-go/applyconfigurations/internal/internal.go
+++ b/staging/src/k8s.io/client-go/applyconfigurations/internal/internal.go
@@ -14363,6 +14363,12 @@ var schemaYAML = typed.YAMLObject(`types:
     - name: gang
       type:
         namedType: io.k8s.api.scheduling.v1alpha1.GangSchedulingPolicy
+    unions:
+    - fields:
+      - fieldName: basic
+        discriminatorValue: Basic
+      - fieldName: gang
+        discriminatorValue: Gang
 - name: io.k8s.api.scheduling.v1alpha1.PriorityClass
   map:
     fields: