diff --git a/src/booking/AirlineInitiatedChanges/mockAirlineInitiatedChanges.ts b/src/booking/AirlineInitiatedChanges/mockAirlineInitiatedChanges.ts
index abf234a1..657eadea 100644
--- a/src/booking/AirlineInitiatedChanges/mockAirlineInitiatedChanges.ts
+++ b/src/booking/AirlineInitiatedChanges/mockAirlineInitiatedChanges.ts
@@ -11,7 +11,6 @@ export const mockAirlineInitiatedChange: AirlineInitiatedChange = {
           penalty_amount: '100.00',
           allowed: true,
         },
-        refund_before_departure: null,
       },
       destination_type: 'airport',
       origin_type: 'airport',
@@ -147,7 +146,6 @@ export const mockAirlineInitiatedChange: AirlineInitiatedChange = {
           penalty_amount: '100.00',
           allowed: true,
         },
-        refund_before_departure: null,
       },
       destination_type: 'airport',
       origin_type: 'airport',
diff --git a/src/booking/Orders/OrdersTypes.ts b/src/booking/Orders/OrdersTypes.ts
index fabfaf78..8e26b131 100644
--- a/src/booking/Orders/OrdersTypes.ts
+++ b/src/booking/Orders/OrdersTypes.ts
@@ -6,16 +6,16 @@ import {
   CabinClass,
   DuffelPassengerGender,
   DuffelPassengerTitle,
-  PassengerType,
   FlightsConditions,
   LoyaltyProgrammeAccount,
   OfferAvailableServiceBaggage,
   OfferAvailableServiceBaggageMetadata,
+  OrderCancellation,
   PassengerIdentityDocumentType,
+  PassengerType,
   PaymentType,
   Place,
   PlaceType,
-  OrderCancellation,
 } from '../../types'
 
 /**
@@ -347,7 +347,7 @@ export interface OrderSlice {
    * The conditions associated with this slice, describing the kinds of modifications you can make and any penalties that will apply to those modifications.
    * This condition is applied only to this slice and to all the passengers associated with this order - for information at the order level (e.g. "what happens if I want to change all the slices?") refer to the `conditions` at the top level. If a particular kind of modification is allowed, you may not always be able to take action through the Duffel API. In some cases, you may need to contact the Duffel support team or the airline directly.
    */
-  conditions: FlightsConditions
+  conditions: Omit<FlightsConditions, 'refund_before_departure'>
   /**
    * The city or airport where this slice ends
    */
diff --git a/src/booking/Orders/mockOrders.ts b/src/booking/Orders/mockOrders.ts
index 8dd17a7d..9a8ce932 100644
--- a/src/booking/Orders/mockOrders.ts
+++ b/src/booking/Orders/mockOrders.ts
@@ -209,7 +209,6 @@ export const mockOrder: Order = {
           penalty_amount: '100.00',
           allowed: true,
         },
-        refund_before_departure: null,
       },
     },
   ],
@@ -423,7 +422,6 @@ export const mockOnHoldOrders: Order[] = [
         },
         conditions: {
           change_before_departure: null,
-          refund_before_departure: null,
         },
       },
     ],
@@ -604,7 +602,6 @@ export const mockOnHoldOrders: Order[] = [
         },
         conditions: {
           change_before_departure: null,
-          refund_before_departure: null,
         },
       },
     ],
diff --git a/src/types/shared.ts b/src/types/shared.ts
index ae1363bc..4e6676b2 100644
--- a/src/types/shared.ts
+++ b/src/types/shared.ts
@@ -78,7 +78,7 @@ export type FlightsConditionAllowed = {
    *
    * @example "GBP"
    */
-  penalty_currency: string
+  penalty_currency: string | null
   /**
    * If the modification is `allowed` then this is the amount payable to apply the modification to all passengers.
    * If there is no penalty, the value will be zero. If the modification isn't `allowed` or the penalty is not known then this field will be `null`.
@@ -86,7 +86,7 @@ export type FlightsConditionAllowed = {
    *
    * @example "100.00"
    */
-  penalty_amount: string
+  penalty_amount: string | null
   /**
    * Whether this kind of modification is allowed post-booking
    *