diff --git a/.stats.yml b/.stats.yml
index 536f39d797c..7a6046dba3b 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,2 +1,2 @@
 configured_endpoints: 1508
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/cloudflare%2Fcloudflare-fc6440a93f6aee5f11262d075db1abe2123bcba78d70b8ec7bb8dd7c8da69401.yml
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/cloudflare%2Fcloudflare-bc8740036f5c85815dd08ce4d1787a79b09e8133dc24fcdf8c594aad2c5cc69d.yml
diff --git a/dns/setting.go b/dns/setting.go
index da0a3560aed..8151f308ee6 100644
--- a/dns/setting.go
+++ b/dns/setting.go
@@ -125,6 +125,8 @@ type SettingEditResponseZoneDefaults struct {
 	FlattenAllCNAMEs bool `json:"flatten_all_cnames"`
 	// Whether to enable Foundation DNS Advanced Nameservers on the zone.
 	FoundationDNS bool `json:"foundation_dns"`
+	// Settings for this internal zone.
+	InternalDNS SettingEditResponseZoneDefaultsInternalDNS `json:"internal_dns"`
 	// Whether to enable multi-provider DNS, which causes Cloudflare to activate the
 	// zone even when non-Cloudflare NS records exist, and to respect NS records at the
 	// zone apex during outbound zone transfers.
@@ -148,6 +150,7 @@ type SettingEditResponseZoneDefaults struct {
 type settingEditResponseZoneDefaultsJSON struct {
 	FlattenAllCNAMEs   apijson.Field
 	FoundationDNS      apijson.Field
+	InternalDNS        apijson.Field
 	MultiProvider      apijson.Field
 	Nameservers        apijson.Field
 	NSTTL              apijson.Field
@@ -166,6 +169,29 @@ func (r settingEditResponseZoneDefaultsJSON) RawJSON() string {
 	return r.raw
 }
 
+// Settings for this internal zone.
+type SettingEditResponseZoneDefaultsInternalDNS struct {
+	// The ID of the zone to fallback to.
+	ReferenceZoneID string                                         `json:"reference_zone_id"`
+	JSON            settingEditResponseZoneDefaultsInternalDNSJSON `json:"-"`
+}
+
+// settingEditResponseZoneDefaultsInternalDNSJSON contains the JSON metadata for
+// the struct [SettingEditResponseZoneDefaultsInternalDNS]
+type settingEditResponseZoneDefaultsInternalDNSJSON struct {
+	ReferenceZoneID apijson.Field
+	raw             string
+	ExtraFields     map[string]apijson.Field
+}
+
+func (r *SettingEditResponseZoneDefaultsInternalDNS) UnmarshalJSON(data []byte) (err error) {
+	return apijson.UnmarshalRoot(data, r)
+}
+
+func (r settingEditResponseZoneDefaultsInternalDNSJSON) RawJSON() string {
+	return r.raw
+}
+
 // Settings determining the nameservers through which the zone should be available.
 type SettingEditResponseZoneDefaultsNameservers struct {
 	// Nameserver type
@@ -296,6 +322,8 @@ type SettingGetResponseZoneDefaults struct {
 	FlattenAllCNAMEs bool `json:"flatten_all_cnames"`
 	// Whether to enable Foundation DNS Advanced Nameservers on the zone.
 	FoundationDNS bool `json:"foundation_dns"`
+	// Settings for this internal zone.
+	InternalDNS SettingGetResponseZoneDefaultsInternalDNS `json:"internal_dns"`
 	// Whether to enable multi-provider DNS, which causes Cloudflare to activate the
 	// zone even when non-Cloudflare NS records exist, and to respect NS records at the
 	// zone apex during outbound zone transfers.
@@ -319,6 +347,7 @@ type SettingGetResponseZoneDefaults struct {
 type settingGetResponseZoneDefaultsJSON struct {
 	FlattenAllCNAMEs   apijson.Field
 	FoundationDNS      apijson.Field
+	InternalDNS        apijson.Field
 	MultiProvider      apijson.Field
 	Nameservers        apijson.Field
 	NSTTL              apijson.Field
@@ -337,6 +366,29 @@ func (r settingGetResponseZoneDefaultsJSON) RawJSON() string {
 	return r.raw
 }
 
+// Settings for this internal zone.
+type SettingGetResponseZoneDefaultsInternalDNS struct {
+	// The ID of the zone to fallback to.
+	ReferenceZoneID string                                        `json:"reference_zone_id"`
+	JSON            settingGetResponseZoneDefaultsInternalDNSJSON `json:"-"`
+}
+
+// settingGetResponseZoneDefaultsInternalDNSJSON contains the JSON metadata for the
+// struct [SettingGetResponseZoneDefaultsInternalDNS]
+type settingGetResponseZoneDefaultsInternalDNSJSON struct {
+	ReferenceZoneID apijson.Field
+	raw             string
+	ExtraFields     map[string]apijson.Field
+}
+
+func (r *SettingGetResponseZoneDefaultsInternalDNS) UnmarshalJSON(data []byte) (err error) {
+	return apijson.UnmarshalRoot(data, r)
+}
+
+func (r settingGetResponseZoneDefaultsInternalDNSJSON) RawJSON() string {
+	return r.raw
+}
+
 // Settings determining the nameservers through which the zone should be available.
 type SettingGetResponseZoneDefaultsNameservers struct {
 	// Nameserver type
@@ -458,6 +510,8 @@ type SettingEditParamsZoneDefaults struct {
 	FlattenAllCNAMEs param.Field[bool] `json:"flatten_all_cnames"`
 	// Whether to enable Foundation DNS Advanced Nameservers on the zone.
 	FoundationDNS param.Field[bool] `json:"foundation_dns"`
+	// Settings for this internal zone.
+	InternalDNS param.Field[SettingEditParamsZoneDefaultsInternalDNS] `json:"internal_dns"`
 	// Whether to enable multi-provider DNS, which causes Cloudflare to activate the
 	// zone even when non-Cloudflare NS records exist, and to respect NS records at the
 	// zone apex during outbound zone transfers.
@@ -479,6 +533,16 @@ func (r SettingEditParamsZoneDefaults) MarshalJSON() (data []byte, err error) {
 	return apijson.MarshalRoot(r)
 }
 
+// Settings for this internal zone.
+type SettingEditParamsZoneDefaultsInternalDNS struct {
+	// The ID of the zone to fallback to.
+	ReferenceZoneID param.Field[string] `json:"reference_zone_id"`
+}
+
+func (r SettingEditParamsZoneDefaultsInternalDNS) MarshalJSON() (data []byte, err error) {
+	return apijson.MarshalRoot(r)
+}
+
 // Settings determining the nameservers through which the zone should be available.
 type SettingEditParamsZoneDefaultsNameservers struct {
 	// Nameserver type
diff --git a/dns/setting_test.go b/dns/setting_test.go
index 60d5dcae9cb..71bba5982d9 100644
--- a/dns/setting_test.go
+++ b/dns/setting_test.go
@@ -33,7 +33,10 @@ func TestSettingEditWithOptionalParams(t *testing.T) {
 		ZoneDefaults: cloudflare.F(dns.SettingEditParamsZoneDefaults{
 			FlattenAllCNAMEs: cloudflare.F(false),
 			FoundationDNS:    cloudflare.F(false),
-			MultiProvider:    cloudflare.F(false),
+			InternalDNS: cloudflare.F(dns.SettingEditParamsZoneDefaultsInternalDNS{
+				ReferenceZoneID: cloudflare.F("reference_zone_id"),
+			}),
+			MultiProvider: cloudflare.F(false),
 			Nameservers: cloudflare.F(dns.SettingEditParamsZoneDefaultsNameservers{
 				Type: cloudflare.F(dns.SettingEditParamsZoneDefaultsNameserversTypeCloudflareStandard),
 			}),