diff --git a/src/rest-client-v5.ts b/src/rest-client-v5.ts
index 2d4fabb..1080c60 100644
--- a/src/rest-client-v5.ts
+++ b/src/rest-client-v5.ts
@@ -69,6 +69,9 @@ import {
   GetOpenInterestParamsV5,
   GetOptionDeliveryPriceParamsV5,
   GetOrderbookParamsV5,
+  GetPreUpgradeClosedPnlParamsV5,
+  GetPreUpgradeOrderHistoryParamsV5,
+  GetPreUpgradeTradeHistoryParamsV5,
   GetPremiumIndexPriceKlineParamsV5,
   GetPublicTradingHistoryParamsV5,
   GetRiskLimitParamsV5,
@@ -656,6 +659,52 @@ export class RestClientV5 extends BaseRestClient {
     return this.getPrivate('/v5/position/closed-pnl', params);
   }
 
+  /**
+   *
+   ****** Pre-upgrade APIs
+   *
+   */
+
+  /**
+   * Get those orders which occurred before you upgrade the account to Unified account.
+   *
+   * For now, it only supports to query USDT perpetual, USDC perpetual, Inverse perpetual and futures.
+   *
+   *   - can get all status in 7 days
+   *   - can only get filled orders beyond 7 days
+   */
+  getPreUpgradeOrderHistory(
+    params: GetPreUpgradeOrderHistoryParamsV5,
+  ): Promise<APIResponseV3WithTime<CategoryCursorListV5<AccountOrderV5[]>>> {
+    return this.getPrivate('/v5/pre-upgrade/order/history', params);
+  }
+
+  /**
+   * Get users' execution records which occurred before you upgrade the account to Unified account, sorted by execTime in descending order
+   *
+   * For now, it only supports to query USDT perpetual, Inverse perpetual and futures.
+   *
+   *   - You may have multiple executions in a single order.
+   *   - You can query by symbol, baseCoin, orderId and orderLinkId, and if you pass multiple params,
+   *      the system will process them according to this priority: orderId > orderLinkId > symbol > baseCoin.
+   */
+  getPreUpgradeTradeHistory(
+    params: GetPreUpgradeTradeHistoryParamsV5,
+  ): Promise<APIResponseV3WithTime<CategoryCursorListV5<ExecutionV5[]>>> {
+    return this.getPrivate('/v5/pre-upgrade/execution/list', params);
+  }
+
+  /**
+   * Query user's closed profit and loss records. The results are sorted by createdTime in descending order.
+   *
+   * For now, it only supports to query USDT perpetual, Inverse perpetual and futures.
+   */
+  getPreUpgradeClosedPnl(
+    params: GetPreUpgradeClosedPnlParamsV5,
+  ): Promise<APIResponseV3WithTime<CategoryCursorListV5<ClosedPnLV5[]>>> {
+    return this.getPrivate('/v5/pre-upgrade/position/closed-pnl', params);
+  }
+
   /**
    *
    ****** Account APIs
diff --git a/src/types/request/index.ts b/src/types/request/index.ts
index 75f8d45..be15ddc 100644
--- a/src/types/request/index.ts
+++ b/src/types/request/index.ts
@@ -12,6 +12,7 @@ export * from './v5-account';
 export * from './v5-asset';
 export * from './v5-market';
 export * from './v5-position';
+export * from './v5-pre-upgrade';
 export * from './v5-trade';
 export * from './v5-user';
 export * from './v5-spot-leverage-token';
diff --git a/src/types/request/v5-pre-upgrade.ts b/src/types/request/v5-pre-upgrade.ts
new file mode 100644
index 0000000..1cb7201
--- /dev/null
+++ b/src/types/request/v5-pre-upgrade.ts
@@ -0,0 +1,37 @@
+import { ExecTypeV5 } from '../v5-shared';
+
+export interface GetPreUpgradeOrderHistoryParamsV5 {
+  category: 'linear' | 'inverse';
+  symbol?: string;
+  baseCoin?: string;
+  orderId?: string;
+  orderLinkId?: string;
+  orderFilter?: 'Order' | 'StopOrder';
+  orderStatus?: string;
+  startTime?: number;
+  endTime?: number;
+  limit?: number;
+  cursor?: string;
+}
+
+export interface GetPreUpgradeTradeHistoryParamsV5 {
+  category: 'linear' | 'inverse';
+  symbol?: string;
+  orderId?: string;
+  orderLinkId?: string;
+  baseCoin?: string;
+  startTime?: number;
+  endTime?: number;
+  execType?: ExecTypeV5;
+  limit?: number;
+  cursor?: string;
+}
+
+export interface GetPreUpgradeClosedPnlParamsV5 {
+  category: 'linear' | 'inverse';
+  symbol: string;
+  startTime?: number;
+  endTime?: number;
+  limit?: number;
+  cursor?: string;
+}
diff --git a/src/types/response/v5-position.ts b/src/types/response/v5-position.ts
index 0ea3a00..66fd0a6 100644
--- a/src/types/response/v5-position.ts
+++ b/src/types/response/v5-position.ts
@@ -94,6 +94,7 @@ export interface ExecutionV5 {
   indexPrice: string;
   underlyingPrice?: string;
   blockTradeId?: string;
+  closedSize?: string;
 }
 
 export interface ClosedPnLV5 {