diff --git a/CHANGELOG b/CHANGELOG
index b2e51af403..f587e26fbe 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Add notification on draft sale
 * Add support for Python 3.10
 * Remove support for Python 3.6
 
diff --git a/__init__.py b/__init__.py
index ee174d54cb..67c6dac9de 100644
--- a/__init__.py
+++ b/__init__.py
@@ -9,4 +9,5 @@ from . import sale
 def register():
     Pool.register(
         sale.Sale,
+        sale.Line,
         module='sale_stock_quantity', type_='model')
diff --git a/message.xml b/message.xml
index 0254d7bb62..70d2af7338 100644
--- a/message.xml
+++ b/message.xml
@@ -6,5 +6,8 @@ this repository contains the full copyright notices and license terms. -->
         <record model="ir.message" id="msg_sale_stock_quantity">
             <field name="text">The forcast quantity (%(forecast_quantity)s%(default_uom)s) for line "%(line)s" is lower than its quantity (%(quantity)s%(unit)s).</field>
         </record>
+        <record model="ir.message" id="msg_product_forecast_quantity_lower">
+            <field name="text">The forecast quantity (%(forecast_quantity)s) of product "%(product)s" is lower than the quantity (%(quantity)s).</field>
+        </record>
     </data>
 </tryton>
diff --git a/sale.py b/sale.py
index fa29793509..6bc3b165d2 100644
--- a/sale.py
+++ b/sale.py
@@ -5,7 +5,7 @@ import datetime
 from collections import defaultdict
 
 from trytond.i18n import gettext
-from trytond.model import ModelView, Workflow
+from trytond.model import ModelView, Workflow, fields
 from trytond.pool import Pool, PoolMeta
 from trytond.tools import grouped_slice
 from trytond.transaction import Transaction
@@ -191,3 +191,54 @@ class Sale(metaclass=PoolMeta):
                         message_values['forecast_quantity'] = forecast_quantity
                         raise_(line.id, message_values)
                     date += datetime.timedelta(1)
+
+
+class Line(metaclass=PoolMeta):
+    __name__ = 'sale.line'
+
+    @fields.depends(methods=['_notify_stock_quantity'])
+    def on_change_notify(self):
+        notifications = super().on_change_notify()
+        notifications.extend(self._notify_stock_quantity())
+        return notifications
+
+    @fields.depends(
+        'sale_state', 'product', 'quantity', 'unit', 'company',
+        'sale', '_parent_sale.warehouse', '_parent_sale.sale_date')
+    def _notify_stock_quantity(self):
+        pool = Pool()
+        Date = pool.get('ir.date')
+        Lang = pool.get('ir.lang')
+        Move = pool.get('stock.move')
+        Product = pool.get('product.product')
+        lang = Lang.get()
+        if (self.sale_state == 'draft'
+                and self.sale
+                and self.product
+                and self.product.type in Move.get_product_types()
+                and self.unit
+                and self.quantity is not None):
+            with Transaction().set_context(
+                    company=self.company.id if self.company else None):
+                today = Date.today()
+            sale_date = self.sale.sale_date or today
+            if self.sale.warehouse:
+                locations = [self.sale.warehouse.id]
+            else:
+                locations = []
+            with Transaction().set_context(
+                    locations=locations,
+                    stock_date_end=sale_date,
+                    uom=self.unit):
+                product = Product(self.product.id)
+                if product.forecast_quantity < self.quantity:
+                    yield ('warning', gettext(
+                            'sale_stock_quantity'
+                            '.msg_product_forecast_quantity_lower',
+                            forecast_quantity=lang.format_number_symbol(
+                                product.forecast_quantity, self.unit,
+                                self.unit.digits),
+                            product=self.product.rec_name,
+                            quantity=lang.format_number_symbol(
+                                self.quantity, self.unit,
+                                self.unit.digits)))
diff --git a/tests/scenario_sale_stock_quantity.rst b/tests/scenario_sale_stock_quantity.rst
index 4325732fab..5a84fd4d1f 100644
--- a/tests/scenario_sale_stock_quantity.rst
+++ b/tests/scenario_sale_stock_quantity.rst
@@ -110,6 +110,8 @@ Sale 3 products with enough stock::
     >>> sale_line = sale.lines.new()
     >>> sale_line.product = product
     >>> sale_line.quantity = 3.0
+    >>> len(sale_line.notifications())
+    0
     >>> sale.click('quote')
 
 Sale 1 product with still enough stock::
@@ -120,6 +122,8 @@ Sale 1 product with still enough stock::
     >>> sale_line = sale.lines.new()
     >>> sale_line.product = product
     >>> sale_line.quantity = 1.0
+    >>> len(sale_line.notifications())
+    0
     >>> sale.click('quote')
 
 Sale 2 more products with not enough stock::
@@ -130,6 +134,8 @@ Sale 2 more products with not enough stock::
     >>> sale_line = sale.lines.new()
     >>> sale_line.product = product
     >>> sale_line.quantity = 2.0
+    >>> len(sale_line.notifications())
+    0
     >>> sale.click('quote') # doctest: +IGNORE_EXCEPTION_DETAIL
     Traceback (most recent call last):
         ...
@@ -147,6 +153,8 @@ Sale 6 products with not enough stock::
     >>> sale_line = sale.lines.new()
     >>> sale_line.product = product
     >>> sale_line.quantity = 6.0
+    >>> len(sale_line.notifications())
+    1
     >>> sale.click('quote') # doctest: +IGNORE_EXCEPTION_DETAIL
     Traceback (most recent call last):
         ...