diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation.go
index 812526c8c96..06a70cd1134 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation.go
@@ -62,7 +62,7 @@ func ValidateCustomResourceDefinition(obj *apiextensions.CustomResourceDefinitio
 	}
 
 	opts := validationOptions{
-		allowDefaults:                            allowDefaults(requestGV),
+		allowDefaults:                            allowDefaults(requestGV, nil),
 		requireRecognizedConversionReviewVersion: true,
 		requireImmutableNames:                    false,
 		requireOpenAPISchema:                     requireOpenAPISchema(requestGV, nil),
@@ -92,7 +92,7 @@ type validationOptions struct {
 // ValidateCustomResourceDefinitionUpdate statically validates
 func ValidateCustomResourceDefinitionUpdate(obj, oldObj *apiextensions.CustomResourceDefinition, requestGV schema.GroupVersion) field.ErrorList {
 	opts := validationOptions{
-		allowDefaults:                            allowDefaults(requestGV) || specHasDefaults(&oldObj.Spec),
+		allowDefaults:                            allowDefaults(requestGV, &oldObj.Spec),
 		requireRecognizedConversionReviewVersion: oldObj.Spec.Conversion == nil || hasValidConversionReviewVersionOrEmpty(oldObj.Spec.Conversion.ConversionReviewVersions),
 		requireImmutableNames:                    apiextensions.IsCRDConditionTrue(oldObj, apiextensions.Established),
 		requireOpenAPISchema:                     requireOpenAPISchema(requestGV, &oldObj.Spec),
@@ -988,10 +988,17 @@ func allVersionsSpecifyOpenAPISchema(spec *apiextensions.CustomResourceDefinitio
 }
 
 // allowDefaults returns true if the defaulting feature is enabled and the request group version allows adding defaults
-func allowDefaults(requestGV schema.GroupVersion) bool {
+func allowDefaults(requestGV schema.GroupVersion, oldCRDSpec *apiextensions.CustomResourceDefinitionSpec) bool {
+	if oldCRDSpec != nil && specHasDefaults(oldCRDSpec) {
+		// don't tighten validation on existing persisted data
+		return true
+	}
 	if !utilfeature.DefaultFeatureGate.Enabled(apiextensionsfeatures.CustomResourceDefaulting) {
 		return false
 	}
+	if requestGV == v1beta1.SchemeGroupVersion {
+		return false
+	}
 	return true
 }
 
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation_test.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation_test.go
index 41d5f567a3c..ee85292bd40 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation_test.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/validation/validation_test.go
@@ -1542,6 +1542,79 @@ func TestValidateCustomResourceDefinition(t *testing.T) {
 				forbidden("spec", "validation", "openAPIV3Schema", "properties[a]", "default"), // disabled feature-gate
 			},
 		},
+		{
+			name: "defaults with enabled feature gate via v1beta1",
+			resource: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{Name: "plural.group.com"},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:    "group.com",
+					Version:  "version",
+					Versions: singleVersionList,
+					Scope:    apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(true),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
+			requestGV:       apiextensionsv1beta1.SchemeGroupVersion,
+			errors: []validationMatch{
+				forbidden("spec", "validation", "openAPIV3Schema", "properties[a]", "default"), // disallowed via v1beta1
+			},
+		},
+		{
+			name: "defaults with enabled feature gate via v1",
+			resource: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{Name: "plural.group.com"},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:    "group.com",
+					Version:  "version",
+					Versions: singleVersionList,
+					Scope:    apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(false),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
+			requestGV:       apiextensionsv1.SchemeGroupVersion,
+		},
 		{
 			name: "x-kubernetes-int-or-string without structural",
 			resource: &apiextensions.CustomResourceDefinition{
@@ -2019,44 +2092,6 @@ func TestValidateCustomResourceDefinition(t *testing.T) {
 
 			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
 		},
-		{
-			name: "defaults with enabled feature gate, structural schema, without pruning",
-			resource: &apiextensions.CustomResourceDefinition{
-				ObjectMeta: metav1.ObjectMeta{Name: "plural.group.com"},
-				Spec: apiextensions.CustomResourceDefinitionSpec{
-					Group:    "group.com",
-					Version:  "version",
-					Versions: singleVersionList,
-					Scope:    apiextensions.NamespaceScoped,
-					Names: apiextensions.CustomResourceDefinitionNames{
-						Plural:   "plural",
-						Singular: "singular",
-						Kind:     "Plural",
-						ListKind: "PluralList",
-					},
-					Validation: &apiextensions.CustomResourceValidation{
-						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
-							Type: "object",
-							Properties: map[string]apiextensions.JSONSchemaProps{
-								"a": {
-									Type:    "number",
-									Default: jsonPtr(42.0),
-								},
-							},
-						},
-					},
-					PreserveUnknownFields: pointer.BoolPtr(true),
-				},
-				Status: apiextensions.CustomResourceDefinitionStatus{
-					StoredVersions: []string{"version"},
-				},
-			},
-			requestGV: apiextensionsv1beta1.SchemeGroupVersion,
-			errors: []validationMatch{
-				invalid("spec", "preserveUnknownFields"),
-			},
-			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
-		},
 		{
 			name: "additionalProperties at resource root",
 			resource: &apiextensions.CustomResourceDefinition{
@@ -3697,7 +3732,7 @@ func TestValidateCustomResourceDefinitionUpdate(t *testing.T) {
 			},
 		},
 		{
-			name: "setting defaults with enabled feature gate",
+			name: "setting defaults with enabled feature gate via v1beta1",
 			old: &apiextensions.CustomResourceDefinition{
 				ObjectMeta: metav1.ObjectMeta{
 					Name:            "plural.group.com",
@@ -3775,11 +3810,95 @@ func TestValidateCustomResourceDefinitionUpdate(t *testing.T) {
 					StoredVersions: []string{"version"},
 				},
 			},
+			requestGV:       apiextensionsv1beta1.SchemeGroupVersion,
+			errors:          []validationMatch{forbidden("spec.validation.openAPIV3Schema.properties[a].default")},
+			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
+		},
+		{
+			name: "setting defaults with enabled feature gate via v1",
+			old: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:            "plural.group.com",
+					ResourceVersion: "42",
+				},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:   "group.com",
+					Version: "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{
+						{
+							Name:    "version",
+							Served:  true,
+							Storage: true,
+						},
+					},
+					Scope: apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type: "number",
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(false),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			resource: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:            "plural.group.com",
+					ResourceVersion: "42",
+				},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:   "group.com",
+					Version: "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{
+						{
+							Name:    "version",
+							Served:  true,
+							Storage: true,
+						},
+					},
+					Scope: apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(false),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			requestGV:       apiextensionsv1.SchemeGroupVersion,
 			errors:          []validationMatch{},
 			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
 		},
 		{
-			name: "ratcheting validation of defaults with disabled feature gate",
+			name: "ratcheting validation of defaults with disabled feature gate via v1beta1",
 			old: &apiextensions.CustomResourceDefinition{
 				ObjectMeta: metav1.ObjectMeta{
 					Name:            "plural.group.com",
@@ -3862,7 +3981,162 @@ func TestValidateCustomResourceDefinitionUpdate(t *testing.T) {
 					StoredVersions: []string{"version"},
 				},
 			},
-			errors: []validationMatch{},
+			requestGV: apiextensionsv1beta1.SchemeGroupVersion,
+			errors:    []validationMatch{},
+		},
+		{
+			name: "ratcheting validation of defaults with disabled feature gate via v1",
+			old: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:            "plural.group.com",
+					ResourceVersion: "42",
+				},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:   "group.com",
+					Version: "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{
+						{
+							Name:    "version",
+							Served:  true,
+							Storage: true,
+						},
+					},
+					Scope: apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(false),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			resource: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:            "plural.group.com",
+					ResourceVersion: "42",
+				},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:   "group.com",
+					Version: "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{
+						{
+							Name:    "version",
+							Served:  true,
+							Storage: true,
+						},
+					},
+					Scope: apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+								"b": {
+									Type:    "number",
+									Default: jsonPtr(43.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(false),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			requestGV: apiextensionsv1.SchemeGroupVersion,
+			errors:    []validationMatch{},
+		},
+		{
+			name: "add default with enabled feature gate, structural schema, without pruning",
+			old: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{Name: "plural.group.com", ResourceVersion: "42"},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:    "group.com",
+					Version:  "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{{Name: "version", Served: true, Storage: true}},
+					Scope:    apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type: "number",
+									//Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(true),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			resource: &apiextensions.CustomResourceDefinition{
+				ObjectMeta: metav1.ObjectMeta{Name: "plural.group.com", ResourceVersion: "42"},
+				Spec: apiextensions.CustomResourceDefinitionSpec{
+					Group:    "group.com",
+					Version:  "version",
+					Versions: []apiextensions.CustomResourceDefinitionVersion{{Name: "version", Served: true, Storage: true}},
+					Scope:    apiextensions.NamespaceScoped,
+					Names: apiextensions.CustomResourceDefinitionNames{
+						Plural:   "plural",
+						Singular: "singular",
+						Kind:     "Plural",
+						ListKind: "PluralList",
+					},
+					Validation: &apiextensions.CustomResourceValidation{
+						OpenAPIV3Schema: &apiextensions.JSONSchemaProps{
+							Type: "object",
+							Properties: map[string]apiextensions.JSONSchemaProps{
+								"a": {
+									Type:    "number",
+									Default: jsonPtr(42.0),
+								},
+							},
+						},
+					},
+					PreserveUnknownFields: pointer.BoolPtr(true),
+				},
+				Status: apiextensions.CustomResourceDefinitionStatus{
+					StoredVersions: []string{"version"},
+				},
+			},
+			errors: []validationMatch{
+				invalid("spec", "preserveUnknownFields"),
+			},
+			enabledFeatures: []featuregate.Feature{features.CustomResourceDefaulting},
 		},
 	}