diff --git a/__init__.py b/__init__.py
index 6bc0934..b3b174b 100644
--- a/__init__.py
+++ b/__init__.py
@@ -14,4 +14,5 @@ def register():
     Pool.register(
         sale.HandleShipmentException,
         sale.HandleInvoiceException,
+        sale.ReturnSale,
         module='sale_product_package', type_='wizard')
diff --git a/sale.py b/sale.py
index 8486def..bcbe00b 100644
--- a/sale.py
+++ b/sale.py
@@ -8,7 +8,7 @@ from trytond.i18n import gettext
 from trytond.exceptions import UserError
 
 __all__ = ['Sale', 'SaleLine',
-    'HandleShipmentException', 'HandleInvoiceException']
+    'HandleShipmentException', 'HandleInvoiceException', 'ReturnSale']
 
 
 class Sale(metaclass=PoolMeta):
@@ -142,3 +142,22 @@ class HandleInvoiceException(metaclass=PoolMeta):
     def transition_handle(self):
         with Transaction().set_context(validate_package=False):
             return super(HandleInvoiceException, self).transition_handle()
+
+
+class ReturnSale(metaclass=PoolMeta):
+    __name__ = 'sale.return_sale'
+
+    def do_return_(self, action):
+        action, data = super().do_return_(action)
+
+        if data.get('res_id'):
+            sales = self.model.browse(data['res_id'])
+
+            for sale in sales:
+                for line in sale.lines:
+                    if line.type == 'line' and line.package_quantity:
+                        line.package_quantity *= -1
+                sale.lines = sale.lines  # Force saving
+            self.model.save(sales)
+
+        return action, data
diff --git a/tests/scenario_sale_product_package.rst b/tests/scenario_sale_product_package.rst
index ca32dd4..ae2f675 100644
--- a/tests/scenario_sale_product_package.rst
+++ b/tests/scenario_sale_product_package.rst
@@ -140,4 +140,24 @@ Sale products with package::
     >>> line.quantity = 12
     >>> line.package_quantity
     2
+    >>> line = sale.lines.new()
+    >>> line.type = 'comment'
+    >>> line.description = 'Test comment'
     >>> sale.save()
+    >>> sale.click('quote')
+    >>> sale.click('confirm')
+    >>> sale.state
+    'processing'
+
+Return sale::
+
+
+  >>> return_sale = Wizard('sale.return_sale', [sale])
+  >>> return_sale.execute('return_')
+  >>> returned_sale, = Sale.find([
+  ...     ('state', '=', 'draft'),
+  ...     ])
+  >>> returned_sale.origin == sale
+  True
+  >>> sorted([(x.quantity or 0, x.package_quantity or 0) for x in returned_sale.lines])
+  [(-12.0, -2), (0, 0)]