diff --git a/modules/account/move.py b/modules/account/move.py
index c357c0e1bd..f817c30500 100644
--- a/modules/account/move.py
+++ b/modules/account/move.py
@@ -634,8 +634,8 @@ class Reconciliation(ModelSQL, ModelView):
     def check_lines(cls, reconciliations):
         Lang = Pool().get('ir.lang')
         for reconciliation in reconciliations:
-            debit = Decimal('0.0')
-            credit = Decimal('0.0')
+            debit = Decimal(0)
+            credit = Decimal(0)
             account = None
             if reconciliation.lines:
                 party = reconciliation.lines[0].party
@@ -1160,13 +1160,13 @@ class Line(DescriptionOriginMixin, MoveLineMixin, ModelSQL, ModelView):
     @fields.depends('debit', 'credit', 'amount_second_currency')
     def on_change_debit(self):
         if self.debit:
-            self.credit = Decimal('0.0')
+            self.credit = Decimal(0)
         self._amount_second_currency_sign()
 
     @fields.depends('debit', 'credit', 'amount_second_currency')
     def on_change_credit(self):
         if self.credit:
-            self.debit = Decimal('0.0')
+            self.debit = Decimal(0)
         self._amount_second_currency_sign()
 
     @fields.depends('amount_second_currency', 'debit', 'credit')
@@ -1547,8 +1547,8 @@ class Line(DescriptionOriginMixin, MoveLineMixin, ModelSQL, ModelView):
             lines = list(lines)
             reconcile_account = None
             reconcile_party = None
-            amount = Decimal('0.0')
-            amount_second_currency = Decimal('0.0')
+            amount = Decimal(0)
+            amount_second_currency = Decimal(0)
             second_currencies = set()
             posted = True
             for line in lines:
@@ -1990,8 +1990,8 @@ class ReconcileLines(Wizard):
     def get_writeoff(self):
         "Return writeoff amount and company"
         company = currency = None
-        amount = Decimal('0.0')
-        amount_second_currency = Decimal('0.0')
+        amount = Decimal(0)
+        amount_second_currency = Decimal(0)
         second_currencies = set()
         for line in self.records:
             amount += line.debit - line.credit
diff --git a/modules/account/tax.py b/modules/account/tax.py
index 3f31fa7086..8b0f695362 100644
--- a/modules/account/tax.py
+++ b/modules/account/tax.py
@@ -1094,7 +1094,7 @@ class Tax(sequence_ordered(), ModelSQL, ModelView, DeactivableMixin):
         '''
         taxes = cls.sort_taxes(taxes)
         res = cls._unit_compute(taxes, price_unit, date)
-        quantity = Decimal(str(quantity or 0.0))
+        quantity = Decimal(str(quantity or 0))
         for row in res:
             row['base'] *= quantity
             row['amount'] *= quantity
diff --git a/modules/account/tests/scenario_account_reconciliation.rst b/modules/account/tests/scenario_account_reconciliation.rst
index 514818b01e..0e0fc57ec7 100644
--- a/modules/account/tests/scenario_account_reconciliation.rst
+++ b/modules/account/tests/scenario_account_reconciliation.rst
@@ -195,4 +195,4 @@ Reconcile Lines with write-off::
     >>> writeoff_line2.account == expense
     True
     >>> writeoff_line2.debit
-    Decimal('3.0')
+    Decimal('3')
diff --git a/modules/account_es/reporting_tax.py b/modules/account_es/reporting_tax.py
index 0cf1c91825..4276fba425 100644
--- a/modules/account_es/reporting_tax.py
+++ b/modules/account_es/reporting_tax.py
@@ -313,7 +313,7 @@ class AEAT303(AEATReport):
                 "computed code %s already defined" % code)
         amounts['46'] = amounts['27'] - amounts['45']
         amounts['64'] = amounts['46'] + amounts['58'] + amounts['76']
-        amounts['66'] = amounts['64'] * Decimal(amounts['65']) / Decimal(100.0)
+        amounts['66'] = amounts['64'] * Decimal(amounts['65']) / Decimal(100)
         amounts['110'] = amounts['78'] = amount_to_compensate
         amounts['87'] = amounts['110'] - amounts['78']
         amounts['69'] = (amounts['66'] + amounts['77'] - amounts['78']
diff --git a/modules/account_invoice/invoice.py b/modules/account_invoice/invoice.py
index 0ac9866c55..c7c3b0a60a 100644
--- a/modules/account_invoice/invoice.py
+++ b/modules/account_invoice/invoice.py
@@ -618,9 +618,9 @@ class Invoice(Workflow, ModelSQL, ModelView, TaxableMixin, InvoiceReportMixin):
         pool = Pool()
         InvoiceTax = pool.get('account.invoice.tax')
 
-        self.untaxed_amount = Decimal('0.0')
-        self.tax_amount = Decimal('0.0')
-        self.total_amount = Decimal('0.0')
+        self.untaxed_amount = Decimal(0)
+        self.tax_amount = Decimal(0)
+        self.total_amount = Decimal(0)
         computed_taxes = {}
 
         if self.lines:
@@ -632,13 +632,13 @@ class Invoice(Workflow, ModelSQL, ModelView, TaxableMixin, InvoiceReportMixin):
             if self.currency:
                 return self.currency.is_zero(amount)
             else:
-                return amount == Decimal('0.0')
+                return amount == Decimal(0)
 
         tax_keys = []
         taxes = list(self.taxes or [])
         for tax in (self.taxes or []):
             if tax.manual:
-                self.tax_amount += tax.amount or Decimal('0.0')
+                self.tax_amount += tax.amount or Decimal(0)
                 continue
             key = tax._key
             if (key not in computed_taxes) or (key in tax_keys):
@@ -646,12 +646,12 @@ class Invoice(Workflow, ModelSQL, ModelView, TaxableMixin, InvoiceReportMixin):
                 continue
             tax_keys.append(key)
             if not is_zero(computed_taxes[key]['base']
-                    - (tax.base or Decimal('0.0'))):
+                    - (tax.base or Decimal(0))):
                 self.tax_amount += computed_taxes[key]['amount']
                 tax.amount = computed_taxes[key]['amount']
                 tax.base = computed_taxes[key]['base']
             else:
-                self.tax_amount += tax.amount or Decimal('0.0')
+                self.tax_amount += tax.amount or Decimal(0)
         for key in computed_taxes:
             if key not in tax_keys:
                 self.tax_amount += computed_taxes[key]['amount']
@@ -2403,8 +2403,8 @@ class InvoiceLine(sequence_ordered(), ModelSQL, ModelView, TaxableMixin):
         if self.type == 'line':
             currency = (self.invoice.currency if self.invoice
                 else self.currency)
-            amount = (Decimal(str(self.quantity or '0.0'))
-                * (self.unit_price or Decimal('0.0')))
+            amount = (Decimal(str(self.quantity or 0))
+                * (self.unit_price or Decimal(0)))
             invoice_type = (
                 self.invoice.type if self.invoice else self.invoice_type)
             if (invoice_type == 'in'
@@ -2419,7 +2419,7 @@ class InvoiceLine(sequence_ordered(), ModelSQL, ModelView, TaxableMixin):
             if currency:
                 return currency.round(amount)
             return amount
-        return Decimal('0.0')
+        return Decimal(0)
 
     def get_amount(self, name):
         if self.type == 'line':
@@ -2898,11 +2898,11 @@ class InvoiceTax(sequence_ordered(), ModelSQL, ModelView):
 
     @staticmethod
     def default_base():
-        return Decimal('0.0')
+        return Decimal(0)
 
     @staticmethod
     def default_amount():
-        return Decimal('0.0')
+        return Decimal(0)
 
     @staticmethod
     def default_manual():
@@ -3359,7 +3359,7 @@ class PayInvoiceAsk(ModelView):
     @fields.depends(
         'lines', 'amount', 'currency', 'invoice', 'payment_lines', 'company')
     def on_change_lines(self):
-        self.amount_writeoff = Decimal('0.0')
+        self.amount_writeoff = Decimal(0)
         if not self.invoice:
             return
 
@@ -3436,7 +3436,7 @@ class PayInvoice(Wizard):
         currency = self.start.currency
         _, remainder = self.get_reconcile_lines_for_amount(
             invoice, amount, currency)
-        if remainder == Decimal('0.0') and amount <= invoice.amount_to_pay:
+        if remainder == Decimal(0) and amount <= invoice.amount_to_pay:
             return 'pay'
         return 'ask'
 
diff --git a/modules/account_invoice/payment_term.py b/modules/account_invoice/payment_term.py
index 359ff17a06..faefc7910b 100644
--- a/modules/account_invoice/payment_term.py
+++ b/modules/account_invoice/payment_term.py
@@ -54,7 +54,7 @@ class PaymentTerm(DeactivableMixin, ModelSQL, ModelView):
         """
         # TODO implement business_days
         # http://pypi.python.org/pypi/BusinessHours/
-        sign = 1 if amount >= Decimal('0.0') else -1
+        sign = 1 if amount >= Decimal(0) else -1
         res = []
         remainder = amount
         for line in self.lines:
@@ -62,7 +62,7 @@ class PaymentTerm(DeactivableMixin, ModelSQL, ModelView):
             value_date = line.get_date(date)
             if value is None or not value_date:
                 continue
-            if ((remainder - value) * sign) < Decimal('0.0'):
+            if ((remainder - value) * sign) < Decimal(0):
                 res.append((value_date, remainder))
                 break
             if value:
@@ -133,16 +133,16 @@ class PaymentTermLine(sequence_ordered(), ModelSQL, ModelView):
     @fields.depends('type')
     def on_change_type(self):
         if self.type != 'fixed':
-            self.amount = Decimal('0.0')
+            self.amount = Decimal(0)
             self.currency = None
         if self.type not in ('percent', 'percent_on_total'):
-            self.ratio = Decimal('0.0')
-            self.divisor = Decimal('0.0')
+            self.ratio = Decimal(0)
+            self.divisor = Decimal(0)
 
     @fields.depends('ratio')
     def on_change_ratio(self):
         if not self.ratio:
-            self.divisor = Decimal('0.0')
+            self.divisor = Decimal(0)
         else:
             self.divisor = self.round(1 / self.ratio,
                 self.__class__.divisor.digits[1])
@@ -150,7 +150,7 @@ class PaymentTermLine(sequence_ordered(), ModelSQL, ModelView):
     @fields.depends('divisor')
     def on_change_divisor(self):
         if not self.divisor:
-            self.ratio = Decimal('0.0')
+            self.ratio = Decimal(0)
         else:
             self.ratio = self.round(1 / self.divisor,
                 self.__class__.ratio.digits[1])
diff --git a/modules/account_statement/statement.py b/modules/account_statement/statement.py
index a117cea061..8a9f382990 100644
--- a/modules/account_statement/statement.py
+++ b/modules/account_statement/statement.py
@@ -830,7 +830,7 @@ class Line(origin_mixin(_states), sequence_ordered(), ModelSQL, ModelView):
         if self.party:
             if self.amount:
                 with Transaction().set_context(date=self.date):
-                    if self.amount > Decimal("0.0"):
+                    if self.amount > Decimal(0):
                         self.account = self.party.account_receivable_used
                     else:
                         self.account = self.party.account_payable_used
@@ -856,7 +856,7 @@ class Line(origin_mixin(_states), sequence_ordered(), ModelSQL, ModelView):
                     # The user has entered a non-default value, we keep it.
                     pass
                 elif self.amount:
-                    if self.amount > Decimal("0.0"):
+                    if self.amount > Decimal(0):
                         self.account = self.party.account_receivable_used
                     else:
                         self.account = self.party.account_payable_used
diff --git a/modules/account_statement_rule/account.py b/modules/account_statement_rule/account.py
index b8ba0da384..25ed887165 100644
--- a/modules/account_statement_rule/account.py
+++ b/modules/account_statement_rule/account.py
@@ -344,7 +344,7 @@ class StatementRuleLine(sequence_ordered(), ModelSQL, ModelView):
                 account = related_to_account
             elif party:
                 with Transaction().set_context(date=origin.date):
-                    if amount > Decimal('0.0'):
+                    if amount > Decimal(0):
                         account = party.account_receivable_used
                     else:
                         account = party.account_payable_used
diff --git a/modules/account_stock_anglo_saxon/invoice.py b/modules/account_stock_anglo_saxon/invoice.py
index ee6e2d23cf..ceacb32943 100644
--- a/modules/account_stock_anglo_saxon/invoice.py
+++ b/modules/account_stock_anglo_saxon/invoice.py
@@ -31,10 +31,10 @@ class InvoiceLine(metaclass=PoolMeta):
 
         if type_.startswith('in_'):
             move_line.debit = amount
-            move_line.credit = Decimal('0.0')
+            move_line.credit = Decimal(0)
             move_line.account = self.product.account_stock_in_used
         else:
-            move_line.debit = Decimal('0.0')
+            move_line.debit = Decimal(0)
             move_line.credit = amount
             move_line.account = self.product.account_stock_out_used
 
diff --git a/modules/account_stock_anglo_saxon/stock.py b/modules/account_stock_anglo_saxon/stock.py
index 2dccd2087d..f3d26b9c8a 100644
--- a/modules/account_stock_anglo_saxon/stock.py
+++ b/modules/account_stock_anglo_saxon/stock.py
@@ -143,7 +143,7 @@ class Move(metaclass=PoolMeta):
             unit, quantity, product.default_uom, round=False)
 
         as_qty_field = _get_field(type_)
-        cost = Decimal('0.0')
+        cost = Decimal(0)
         consumed_qty = 0.0
         for move, move_qty, move_cost_price in cls._get_anglo_saxon_move(
                 moves, total_qty, type_):
diff --git a/modules/account_stock_continental/stock.py b/modules/account_stock_continental/stock.py
index 45af021712..d80dc1752e 100644
--- a/modules/account_stock_continental/stock.py
+++ b/modules/account_stock_continental/stock.py
@@ -37,12 +37,12 @@ class Move(metaclass=PoolMeta):
                 Decimal(str(self.quantity)) * unit_price)
 
         if type_.startswith('in_'):
-            move_line.debit = Decimal('0.0')
+            move_line.debit = Decimal(0)
             move_line.credit = amount
             move_line.account = self.product.account_stock_in_used
         else:
             move_line.debit = amount
-            move_line.credit = Decimal('0.0')
+            move_line.credit = Decimal(0)
             move_line.account = self.product.account_stock_out_used
 
         return [move_line]
@@ -58,12 +58,12 @@ class Move(metaclass=PoolMeta):
             )
         if not amount:
             return
-        if amount >= Decimal('0.0'):
-            move_line.debit = Decimal('0.0')
+        if amount >= Decimal(0):
+            move_line.debit = Decimal(0)
             move_line.credit = amount
         else:
             move_line.debit = - amount
-            move_line.credit = Decimal('0.0')
+            move_line.credit = Decimal(0)
         return move_line
 
     def _get_account_stock_move_type(self):
@@ -141,7 +141,7 @@ class Move(metaclass=PoolMeta):
             else:
                 account_move_lines = self._get_account_stock_move_lines(type_)
 
-        amount = Decimal('0.0')
+        amount = Decimal(0)
         for line in account_move_lines:
             amount += line.debit - line.credit
 
diff --git a/modules/analytic_account/account.py b/modules/analytic_account/account.py
index b2fa817eb7..d004b5b874 100644
--- a/modules/analytic_account/account.py
+++ b/modules/analytic_account/account.py
@@ -232,7 +232,7 @@ class Account(
         for name in names:
             if name not in ('credit', 'debit'):
                 raise Exception('Bad argument')
-            result[name] = {}.fromkeys(ids, Decimal('0.0'))
+            result[name] = {}.fromkeys(ids, Decimal(0))
 
         id2account = {}
         for account in accounts:
diff --git a/modules/currency/currency.py b/modules/currency/currency.py
index b66680bb04..1332cc13a6 100644
--- a/modules/currency/currency.py
+++ b/modules/currency/currency.py
@@ -120,7 +120,7 @@ class Currency(
     def on_change_with_rate(self):
         now = datetime.date.today()
         closer = datetime.date.min
-        res = Decimal('0.0')
+        res = Decimal(0)
         for rate in self.rates or []:
             date = getattr(rate, 'date', None) or now
             if date <= now and date > closer:
diff --git a/modules/product_cost_fifo/move.py b/modules/product_cost_fifo/move.py
index 77c8295b29..e4169ad1bf 100644
--- a/modules/product_cost_fifo/move.py
+++ b/modules/product_cost_fifo/move.py
@@ -83,7 +83,7 @@ class Move(metaclass=PoolMeta):
         with Transaction().set_context(company=self.company.id):
             fifo_moves = self.product.get_fifo_move(total_qty)
 
-        cost_price = Decimal("0.0")
+        cost_price = Decimal(0)
         consumed_qty = 0.0
         to_save = []
         for move, move_qty in fifo_moves:
diff --git a/modules/purchase/purchase.py b/modules/purchase/purchase.py
index ad24810af9..272baa4d08 100644
--- a/modules/purchase/purchase.py
+++ b/modules/purchase/purchase.py
@@ -468,9 +468,9 @@ class Purchase(
 
     @fields.depends('lines', 'currency', methods=['get_tax_amount'])
     def on_change_lines(self):
-        self.untaxed_amount = Decimal('0.0')
-        self.tax_amount = Decimal('0.0')
-        self.total_amount = Decimal('0.0')
+        self.untaxed_amount = Decimal(0)
+        self.tax_amount = Decimal(0)
+        self.total_amount = Decimal(0)
         if self.lines:
             for line in self.lines:
                 self.untaxed_amount += getattr(line, 'amount', None) or 0
@@ -1533,7 +1533,7 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
         if self.type == 'line':
             return self.on_change_with_amount()
         elif self.type == 'subtotal':
-            amount = Decimal('0.0')
+            amount = Decimal(0)
             for line2 in self.purchase.lines:
                 if line2.type == 'line':
                     amount += line2.purchase.currency.round(
@@ -1541,7 +1541,7 @@ class Line(sequence_ordered(), ModelSQL, ModelView):
                 elif line2.type == 'subtotal':
                     if self == line2:
                         break
-                    amount = Decimal('0.0')
+                    amount = Decimal(0)
             return amount
 
     @fields.depends('purchase', '_parent_purchase.warehouse')
diff --git a/modules/purchase_blanket_agreement/purchase.py b/modules/purchase_blanket_agreement/purchase.py
index c494b3b0de..287f9afd73 100644
--- a/modules/purchase_blanket_agreement/purchase.py
+++ b/modules/purchase_blanket_agreement/purchase.py
@@ -568,8 +568,8 @@ class BlanketAgreementLine(ModelSQL, ModelView):
         '_parent_blanket_agreement.currency')
     def on_change_with_amount(self, name=None):
         amount = (
-            Decimal(str(self.quantity or '0.0'))
-            * (self.unit_price or Decimal('0.0')))
+            Decimal(str(self.quantity or 0))
+            * (self.unit_price or Decimal(0)))
 
         if self.blanket_agreement and self.blanket_agreement.currency:
             return self.blanket_agreement.currency.round(amount)
diff --git a/modules/purchase_requisition/purchase.py b/modules/purchase_requisition/purchase.py
index b80e9e9f47..d74e148812 100644
--- a/modules/purchase_requisition/purchase.py
+++ b/modules/purchase_requisition/purchase.py
@@ -234,7 +234,7 @@ class PurchaseRequisition(Workflow, ModelSQL, ModelView):
 
     @fields.depends('lines', 'currency')
     def on_change_with_total_amount(self):
-        self.total_amount = Decimal('0.0')
+        self.total_amount = Decimal(0)
         if self.lines:
             for line in self.lines:
                 self.total_amount += getattr(line, 'amount', None) or 0
diff --git a/modules/sale/sale.py b/modules/sale/sale.py
index 7b27bbc105..41c099a173 100644
--- a/modules/sale/sale.py
+++ b/modules/sale/sale.py
@@ -528,9 +528,9 @@ class Sale(
 
     @fields.depends('lines', 'currency', methods=['get_tax_amount'])
     def on_change_lines(self):
-        self.untaxed_amount = Decimal('0.0')
-        self.tax_amount = Decimal('0.0')
-        self.total_amount = Decimal('0.0')
+        self.untaxed_amount = Decimal(0)
+        self.tax_amount = Decimal(0)
+        self.total_amount = Decimal(0)
 
         if self.lines:
             for line in self.lines:
@@ -1583,18 +1583,18 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
     def on_change_with_amount(self):
         if self.type == 'line':
             currency = self.sale.currency if self.sale else None
-            amount = Decimal(str(self.quantity or '0.0')) * \
-                (self.unit_price or Decimal('0.0'))
+            amount = Decimal(str(self.quantity or 0)) * \
+                (self.unit_price or Decimal(0))
             if currency:
                 return currency.round(amount)
             return amount
-        return Decimal('0.0')
+        return Decimal(0)
 
     def get_amount(self, name):
         if self.type == 'line':
             return self.on_change_with_amount()
         elif self.type == 'subtotal':
-            amount = Decimal('0.0')
+            amount = Decimal(0)
             for line2 in self.sale.lines:
                 if line2.type == 'line':
                     amount += line2.sale.currency.round(
@@ -1602,9 +1602,9 @@ class SaleLine(TaxableMixin, sequence_ordered(), ModelSQL, ModelView):
                 elif line2.type == 'subtotal':
                     if self == line2:
                         break
-                    amount = Decimal('0.0')
+                    amount = Decimal(0)
             return amount
-        return Decimal('0.0')
+        return Decimal(0)
 
     @fields.depends('sale', '_parent_sale.warehouse')
     def on_change_with_warehouse(self, name=None):
diff --git a/modules/sale_blanket_agreement/sale.py b/modules/sale_blanket_agreement/sale.py
index 0292056a9e..2e2cd54885 100644
--- a/modules/sale_blanket_agreement/sale.py
+++ b/modules/sale_blanket_agreement/sale.py
@@ -521,8 +521,8 @@ class BlanketAgreementLine(ModelSQL, ModelView):
         '_parent_blanket_agreement.currency')
     def on_change_with_amount(self, name=None):
         amount = (
-            Decimal(str(self.quantity or '0.0'))
-            * (self.unit_price or Decimal('0.0')))
+            Decimal(str(self.quantity or 0))
+            * (self.unit_price or Decimal(0)))
 
         if self.blanket_agreement and self.blanket_agreement.currency:
             return self.blanket_agreement.currency.round(amount)