diff --git a/types/2019-12-03/Customers.d.ts b/types/2019-12-03/Customers.d.ts
index 3ea0d61638..357a183c94 100644
--- a/types/2019-12-03/Customers.d.ts
+++ b/types/2019-12-03/Customers.d.ts
@@ -283,7 +283,7 @@ declare module 'stripe' {
         /**
          * Default custom fields to be displayed on invoices for this customer. When updating, pass an empty string to remove previously-defined fields.
          */
-        custom_fields?: InvoiceSettings.CustomFields | null;
+        custom_fields?: Array<InvoiceSettings.CustomField> | '';
 
         /**
          * ID of a payment method that's attached to the customer, to be used as the customer's default payment method for subscriptions and invoices.
@@ -297,7 +297,7 @@ declare module 'stripe' {
       }
 
       namespace InvoiceSettings {
-        interface CustomFields {
+        interface CustomField {
           /**
            * The name of the custom field. This may be up to 30 characters.
            */
@@ -464,7 +464,7 @@ declare module 'stripe' {
         /**
          * Default custom fields to be displayed on invoices for this customer. When updating, pass an empty string to remove previously-defined fields.
          */
-        custom_fields?: InvoiceSettings.CustomFields | null;
+        custom_fields?: Array<InvoiceSettings.CustomField> | '';
 
         /**
          * ID of a payment method that's attached to the customer, to be used as the customer's default payment method for subscriptions and invoices.
@@ -478,7 +478,7 @@ declare module 'stripe' {
       }
 
       namespace InvoiceSettings {
-        interface CustomFields {
+        interface CustomField {
           /**
            * The name of the custom field. This may be up to 30 characters.
            */
diff --git a/types/2019-12-03/Invoices.d.ts b/types/2019-12-03/Invoices.d.ts
index 36920f22be..66c3b225a7 100644
--- a/types/2019-12-03/Invoices.d.ts
+++ b/types/2019-12-03/Invoices.d.ts
@@ -319,18 +319,6 @@ declare module 'stripe' {
 
       type CollectionMethod = 'charge_automatically' | 'send_invoice';
 
-      interface CustomField {
-        /**
-         * The name of the custom field.
-         */
-        name: string;
-
-        /**
-         * The value of the custom field.
-         */
-        value: string;
-      }
-
       interface CustomerShipping {
         address?: Address;
 
@@ -395,6 +383,18 @@ declare module 'stripe' {
           | 'za_vat';
       }
 
+      interface CustomField {
+        /**
+         * The name of the custom field.
+         */
+        name: string;
+
+        /**
+         * The value of the custom field.
+         */
+        value: string;
+      }
+
       type Status =
         | 'deleted'
         | 'draft'
@@ -520,7 +520,7 @@ declare module 'stripe' {
       /**
        * A list of up to 4 custom fields to be displayed on the invoice.
        */
-      custom_fields?: InvoiceCreateParams.CustomFields | null;
+      custom_fields?: Array<InvoiceCreateParams.CustomField> | '';
 
       /**
        * The number of days from when the invoice is created until it is due. Valid only for invoices where `collection_method=send_invoice`.
@@ -591,7 +591,7 @@ declare module 'stripe' {
     namespace InvoiceCreateParams {
       type CollectionMethod = 'charge_automatically' | 'send_invoice';
 
-      interface CustomFields {
+      interface CustomField {
         /**
          * The name of the custom field. This may be up to 30 characters.
          */
@@ -637,7 +637,7 @@ declare module 'stripe' {
       /**
        * A list of up to 4 custom fields to be displayed on the invoice. If a value for `custom_fields` is specified, the list specified will replace the existing custom field list on this invoice. Pass an empty string to remove previously-defined fields.
        */
-      custom_fields?: InvoiceUpdateParams.CustomFields | null;
+      custom_fields?: Array<InvoiceUpdateParams.CustomField> | '';
 
       /**
        * The number of days from which the invoice is created until it is due. Only valid for invoices where `collection_method=send_invoice`. This field can only be updated on `draft` invoices.
@@ -697,13 +697,13 @@ declare module 'stripe' {
       /**
        * If specified, the funds from the invoice will be transferred to the destination and the ID of the resulting transfer will be found on the invoice's charge. This will be unset if you POST an empty value.
        */
-      transfer_data?: InvoiceUpdateParams.TransferData | null;
+      transfer_data?: InvoiceUpdateParams.TransferData | '';
     }
 
     namespace InvoiceUpdateParams {
       type CollectionMethod = 'charge_automatically' | 'send_invoice';
 
-      interface CustomFields {
+      interface CustomField {
         /**
          * The name of the custom field. This may be up to 30 characters.
          */
diff --git a/types/2019-12-03/Orders.d.ts b/types/2019-12-03/Orders.d.ts
index 7c18870969..0ef6983e60 100644
--- a/types/2019-12-03/Orders.d.ts
+++ b/types/2019-12-03/Orders.d.ts
@@ -461,11 +461,11 @@ declare module 'stripe' {
       /**
        * List of items to return.
        */
-      items?: OrderReturnOrderParams.Items | null;
+      items?: Array<OrderReturnOrderParams.Item> | '';
     }
 
     namespace OrderReturnOrderParams {
-      interface Items {
+      interface Item {
         /**
          * The amount (price) for this order item to return.
          */
@@ -489,10 +489,10 @@ declare module 'stripe' {
         /**
          * The type of this order item. Must be `sku`, `tax`, or `shipping`.
          */
-        type?: Items.Type;
+        type?: Item.Type;
       }
 
-      namespace Items {
+      namespace Item {
         type Type = 'discount' | 'shipping' | 'sku' | 'tax';
       }
     }