diff --git a/modules/ticket/back/methods/sale/specs/updateDiscount.spec.js b/modules/ticket/back/methods/sale/specs/updateDiscount.spec.js
new file mode 100644
index 000000000..69f1a11ff
--- /dev/null
+++ b/modules/ticket/back/methods/sale/specs/updateDiscount.spec.js
@@ -0,0 +1,82 @@
+const app = require('vn-loopback/server/server');
+
+// #1486 back test updateDiscount
+xdescribe('sale updateDiscount()', () => {
+    let originalSale;
+    let createdSaleComponent;
+
+    afterAll(async done => {
+        originalSale.save();
+        createdSaleComponent.destroy();
+        done();
+    });
+
+
+    it('should throw an error if any sale discount is not a number', async() => {
+        let error;
+        const ticketId = 1;
+        const sales = [
+            {discount: 'pepinillos'}
+        ];
+
+        try {
+            await app.models.Sale.updateDiscount(ticketId, sales);
+        } catch (err) {
+            error = err;
+        }
+
+        expect(error.message).toEqual('The value should be a number');
+    });
+
+    it('should throw an error if the ticket is invoiced already', async() => {
+        let error;
+        const ticketId = 7;
+        const sales = [
+            {discount: 100}
+        ];
+
+        try {
+            await app.models.Sale.updateDiscount(ticketId, sales);
+        } catch (err) {
+            error = err;
+        }
+
+        expect(error.message).toEqual(`The sales of this ticket can't be modified`);
+    });
+
+    it('should update the discount if the salesPerson has mana', async() => {
+        const saleId = 1;
+        originalSale = await app.models.Sale.findById(saleId);
+
+        let manaDiscount = await app.models.ComponentRate.findOne({where: {code: 'mana'}});
+        let componentId = manaDiscount.id;
+        createdSaleComponent = await app.models.SaleComponent.findOne({
+            where: {
+                componentFk: componentId,
+                saleFk: saleId
+            }
+        });
+
+        expect(createdSaleComponent).toBeNull();
+
+        const ticketId = 8;
+        const sales = [
+            {
+                id: saleId,
+                discount: 100}
+        ];
+
+        await app.models.Sale.updateDiscount(ticketId, sales);
+
+        let updatedSale = await app.models.Sale.findById(saleId);
+        createdSaleComponent = await app.models.SaleComponent.findOne({
+            where: {
+                componentFk: componentId,
+                saleFk: saleId
+            }
+        });
+
+        expect(createdSaleComponent.componentFk).toEqual(componentId);
+        expect(updatedSale.discount).toEqual(100);
+    });
+});