diff --git a/tryton/modules/sale_credit_limit/__init__.py b/tryton/modules/sale_credit_limit/__init__.py
index 78da1b6ee0..8ebdad6e3e 100644
--- a/tryton/modules/sale_credit_limit/__init__.py
+++ b/tryton/modules/sale_credit_limit/__init__.py
@@ -10,4 +10,5 @@ def register():
     Pool.register(
         party.Party,
         sale.Sale,
+        sale.Line,
         module='sale_credit_limit', type_='model')
diff --git a/tryton/modules/sale_credit_limit/party.py b/tryton/modules/sale_credit_limit/party.py
index ea1a823053..0ecc449813 100644
--- a/tryton/modules/sale_credit_limit/party.py
+++ b/tryton/modules/sale_credit_limit/party.py
@@ -31,8 +31,8 @@ class Party(metaclass=PoolMeta):
         for sale in sales:
             amount = 0
             for line in sale.lines:
-                quantity = line.quantity
-                if not quantity or (line.type != 'line'):
+                quantity = line.credit_limit_quantity
+                if quantity is None:
                     continue
                 for invoice_line in line.invoice_lines:
                     if invoice_line.type != 'line':
@@ -42,10 +42,11 @@ class Party(metaclass=PoolMeta):
                         quantity -= Uom.compute_qty(
                             invoice_line.unit, invoice_line.quantity,
                             line.unit, round=False)
-                amount += Currency.compute(
-                    sale.currency,
-                    Decimal(str(quantity)) * line.unit_price, currency,
-                    round=False)
+                if quantity > 0:
+                    amount += Currency.compute(
+                        sale.currency,
+                        Decimal(str(quantity)) * line.unit_price, currency,
+                        round=False)
             amounts[sale.party.id] = currency.round(
                 amounts[sale.party.id] + amount)
         return amounts
diff --git a/tryton/modules/sale_credit_limit/sale.py b/tryton/modules/sale_credit_limit/sale.py
index d209f7268f..37c94d53ec 100644
--- a/tryton/modules/sale_credit_limit/sale.py
+++ b/tryton/modules/sale_credit_limit/sale.py
@@ -1,7 +1,7 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
 from trytond.model import ModelView, Workflow
-from trytond.pool import PoolMeta
+from trytond.pool import Pool, PoolMeta


 class Sale(metaclass=PoolMeta):
@@ -25,3 +25,25 @@ class Sale(metaclass=PoolMeta):
                 party.check_credit_limit(
                     sale.credit_limit_amount, origin=str(sale))
         super(Sale, cls).confirm(sales)
+
+
+class Line(metaclass=PoolMeta):
+    __name__ = 'sale.line'
+
+    @property
+    def credit_limit_quantity(self):
+        pool = Pool()
+        UoM = pool.get('product.uom')
+        if (self.type != 'line') or (self.quantity <= 0):
+            return None
+        quantity = self.quantity
+        if self.sale.invoice_method == 'shipment':
+            for move in self.moves_ignored:
+                quantity -= UoM.compute_qty(
+                    move.uom, move.quantity, self.unit, round=False)
+        for invoice_line in self.invoice_lines:
+            if invoice_line.invoice in self.sale.invoices_ignored:
+                quantity -= UoM.compute_qty(
+                    invoice_line.unit, invoice_line.quantity, self.unit,
+                    round=False)
+        return quantity
diff --git a/tryton/modules/sale_credit_limit/tests/test_module.py b/tryton/modules/sale_credit_limit/tests/test_module.py
index 31fde1e612..491fba12d3 100644
--- a/tryton/modules/sale_credit_limit/tests/test_module.py
+++ b/tryton/modules/sale_credit_limit/tests/test_module.py
@@ -88,8 +88,8 @@ class SaleCreditLimitTestCase(CompanyTestMixin, ModuleTestCase):
                         'lines': [
                             ('create', [{
                                         'description': 'Test',
-                                        'quantity': 1,
-                                        'unit_price': Decimal('50'),
+                                        'quantity': 2,
+                                        'unit_price': Decimal('25'),
                                         }]),
                             ],
                         }])
@@ -117,7 +117,7 @@ class SaleCreditLimitTestCase(CompanyTestMixin, ModuleTestCase):
             # Increase quantity invoiced does not change the credit amount
             invoice, = sale.invoices
             invoice_line, = invoice.lines
-            invoice_line.quantity += 1
+            invoice_line.quantity = 1
             invoice_line.save()
             Invoice.post([invoice])
             self.assertEqual(party.credit_amount, Decimal('150'))