diff --git a/sale_triple_discount/models/sale_order_line.py b/sale_triple_discount/models/sale_order_line.py
index 493292f78a4..fa5c5ed9e8a 100644
--- a/sale_triple_discount/models/sale_order_line.py
+++ b/sale_triple_discount/models/sale_order_line.py
@@ -4,42 +4,12 @@
 # Copyright 2018 ~ 2021 Simone Rubino - Agile Business Group
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
-from odoo import api, fields, models
-import odoo.addons.decimal_precision as dp
+from odoo import api, models
 
 
 class SaleOrderLine(models.Model):
-    _inherit = "sale.order.line"
-
-    def _get_final_discount(self):
-        self.ensure_one()
-        if self.discounting_type == "additive":
-            return self._additive_discount()
-        elif self.discounting_type == "multiplicative":
-            return self._multiplicative_discount()
-
-    def _additive_discount(self):
-        self.ensure_one()
-        discount = sum(
-            [getattr(self, x) or 0.0 for x in self._discount_fields()]
-        )
-        if discount <= 0:
-            return 0
-        elif discount >= 100:
-            return 100
-        return discount
-
-    def _multiplicative_discount(self):
-        self.ensure_one()
-        discounts = [1 - (self[x] or 0.0) / 100
-                     for x in self._discount_fields()]
-        final_discount = 1
-        for discount in discounts:
-            final_discount *= discount
-        return 100 - final_discount * 100
-
-    def _discount_fields(self):
-        return ['discount', 'discount2', 'discount3']
+    _name = "sale.order.line"
+    _inherit = ["line.triple_discount.mixin", "sale.order.line"]
 
     @api.depends('discount2', 'discount3', 'discounting_type')
     def _compute_amount(self):
@@ -48,45 +18,6 @@ def _compute_amount(self):
             super(SaleOrderLine, line)._compute_amount()
             line.triple_discount_postprocess(prev_values)
 
-    discount2 = fields.Float(
-        'Disc. 2 (%)',
-        digits=dp.get_precision('Discount'),
-        default=0.0,
-    )
-    discount3 = fields.Float(
-        'Disc. 3 (%)',
-        digits=dp.get_precision('Discount'),
-        default=0.0,
-    )
-    discounting_type = fields.Selection(
-        string="Discounting type",
-        selection=[
-            ('additive', 'Additive'),
-            ('multiplicative', 'Multiplicative'),
-        ],
-        default="multiplicative",
-        required=True,
-        help="Specifies whether discounts should be additive "
-        "or multiplicative.\nAdditive discounts are summed first and "
-        "then applied.\nMultiplicative discounts are applied sequentially.\n"
-        "Multiplicative discounts are default",
-    )
-
-    _sql_constraints = [
-        ('discount2_limit', 'CHECK (discount2 <= 100.0)',
-         'Discount 2 must be lower than 100%.'),
-        ('discount3_limit', 'CHECK (discount3 <= 100.0)',
-         'Discount 3 must be lower than 100%.'),
-    ]
-
-    def _get_triple_discount(self):
-        """Get the discount that is equivalent to the subsequent application
-        of discount, discount2 and discount3"""
-        discount_factor = 1.0
-        for discount in [self.discount, self.discount2, self.discount3]:
-            discount_factor *= (100.0 - discount) / 100.0
-        return 100.0 - (discount_factor * 100.0)
-
     def _prepare_invoice_line(self, qty):
         res = super(SaleOrderLine, self)._prepare_invoice_line(qty)
         res.update({
@@ -100,30 +31,3 @@ def _get_price_reduce(self):
         prev_values = self.triple_discount_preprocess()
         super(SaleOrderLine, self)._get_price_reduce()
         self.triple_discount_postprocess(prev_values)
-
-    @api.multi
-    def triple_discount_preprocess(self):
-        """Save the values of the discounts in a dictionary,
-        to be restored in postprocess.
-        Resetting discount2 and discount3 to 0.0 avoids issues if
-        this method is called multiple times."""
-        prev_values = dict()
-
-        for line in self:
-            prev_values[line] = dict(
-                discount=line.discount,
-                discount2=line.discount2,
-                discount3=line.discount3,
-            )
-            line.update({
-                'discount': line._get_final_discount(),
-                'discount2': 0.0,
-                'discount3': 0.0
-            })
-        return prev_values
-
-    @api.model
-    def triple_discount_postprocess(self, prev_values):
-        """Restore the discounts of the lines in the dictionary prev_values."""
-        for line, prev_vals_dict in list(prev_values.items()):
-            line.update(prev_vals_dict)
diff --git a/sale_triple_discount/tests/test_sale_triple_discount.py b/sale_triple_discount/tests/test_sale_triple_discount.py
index 1577c1d566b..3ded85a4111 100644
--- a/sale_triple_discount/tests/test_sale_triple_discount.py
+++ b/sale_triple_discount/tests/test_sale_triple_discount.py
@@ -150,3 +150,19 @@ def test_05_round_globally(self):
         self.assertEqual(self.so_line2.price_subtotal, 300.0)
         self.assertEqual(self.order.amount_untaxed, 375.0)
         self.assertEqual(self.order.amount_tax, 56.25)
+
+    def test_06_discounts(self):
+        """ Tests discounts in edge case """
+        order = self.env['sale.order'].create({
+            'partner_id': self.partner.id,
+            'order_line': [(0, 0, {
+                'name': 'Line 1',
+                'product_id': self.product2.id,
+                'price_unit': 25.0,
+                'product_uom_qty': 65,
+                'discount': 50,
+                'discount2': 13,
+                'discount3': 0,
+            })],
+        })
+        self.assertEqual(order.order_line.price_subtotal, 706.88)