diff --git a/src/client.ts b/src/client.ts
index 665fe0f..9d145c3 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -75,7 +75,9 @@ export class Client {
 
   // Must login first
   async replacePrice(placedOrder: PlacedOrder, price: number | PriceFlag): Promise<ReplaceOrderResponse> {
-    const order = placedOrder.toObject();
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const unit = this.sdk.getVolumePerUnit(placedOrder.payload.stockNo!);
+    const order = placedOrder.toModifiedObject(unit);
     const response = (typeof price === 'number')
       ? this.sdk.modifyPrice(order, price, PriceFlag.Limit)
       : this.sdk.modifyPrice(order, null, price);
@@ -85,7 +87,9 @@ export class Client {
 
   // Must login first
   async replaceQuantity(placedOrder: PlacedOrder, quantity: number): Promise<ReplaceOrderResponse> {
-    const order = placedOrder.toObject();
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const unit = this.sdk.getVolumePerUnit(placedOrder.payload.stockNo!);
+    const order = placedOrder.toModifiedObject(unit);
     const response = this.sdk.modifyVolume(order, quantity);
     const parsed = JSON.parse(response) as ParsedReplaceOrderResponse;
     return parsed.data;
diff --git a/src/placed-order.ts b/src/placed-order.ts
index d220d24..84d2ef8 100644
--- a/src/placed-order.ts
+++ b/src/placed-order.ts
@@ -47,4 +47,18 @@ export class PlacedOrder {
         {} as OrderResult,
       );
   }
+
+  toModifiedObject(unit: number): OrderResult {
+    return Object.entries(this.payload).reduce((object, [key, value]) => {
+      if (
+        key.endsWith("Qty") &&
+        this.payload.apCode &&
+        [ApCode.Odd, ApCode.Emg, ApCode.IntradayOdd].includes(
+          this.payload.apCode
+        )
+      )
+        return { ...object, [key]: String(Math.floor(value * unit)) };
+      return { ...object, [key]: String(value) };
+    }, {} as OrderResult);
+  }
 }
diff --git a/test/placed-order.spec.ts b/test/placed-order.spec.ts
index 024847f..46d3dcb 100644
--- a/test/placed-order.spec.ts
+++ b/test/placed-order.spec.ts
@@ -85,4 +85,55 @@ describe('PlacedOrder', () => {
       });
     });
   });
+
+  describe('.toModifiedObject()', () => {
+    it('should return ModifiedObject', () => {
+      const placedOrder = new PlacedOrder({
+        workDate: '20220222',
+        ordDate: '20220222',
+        ordTime: '130000000',
+        ordStatus: '2',
+        ordNo: 'B9999',
+        preOrdNo: '',
+        stockNo: '0050',
+        buySell: 'B',
+        apCode: '5',
+        priceFlag: '0',
+        trade: '0',
+        odPrice: '140.0',
+        orgQty: '0.001',
+        matQty: '0',
+        celQty: '0',
+        celable: '2',
+        errCode: '00000000',
+        errMsg: '',
+        avgPrice: '0.0',
+        bsFlag: 'R',
+      });
+
+      expect(placedOrder.toModifiedObject(1000)).toEqual({
+        workDate: '20220222',
+        ordDate: '20220222',
+        ordTime: '130000000',
+        ordStatus: '2',
+        ordNo: 'B9999',
+        preOrdNo: '',
+        stockNo: '0050',
+        buySell: 'B',
+        apCode: '5',
+        priceFlag: '0',
+        trade: '0',
+        odPrice: '140',
+        orgQty: '1',
+        matQty: '0',
+        celQty: '0',
+        celable: '2',
+        errCode: '00000000',
+        errMsg: '',
+        avgPrice: '0',
+        bsFlag: 'R',
+      });
+    });
+  });
+  
 });