diff --git a/commission.py b/commission.py
index 2a1709f330..cceaf1086d 100644
--- a/commission.py
+++ b/commission.py
@@ -20,7 +20,7 @@ from trytond.pool import Pool
 from trytond.wizard import Wizard, StateView, StateAction, Button
 from trytond.transaction import Transaction
 
-from trytond.modules.product import price_digits
+from trytond.modules.product import price_digits, round_price
 
 from .exceptions import FormulaError
 
@@ -122,14 +122,12 @@ class Agent(ModelSQL, ModelView):
                 group_by=commission.agent)
             cursor.execute(*query)
             amounts.update(dict(cursor.fetchall()))
-        digits = cls.pending_amount.digits
-        exp = Decimal(str(10.0 ** -digits[1]))
         for agent_id, amount in amounts.items():
             if amount:
                 # SQLite uses float for SUM
                 if not isinstance(amount, Decimal):
                     amount = Decimal(str(amount))
-                amounts[agent_id] = amount.quantize(exp)
+                amounts[agent_id] = round_price(amount)
         return amounts
 
     @property
diff --git a/invoice.py b/invoice.py
index 36a3cdd3b5..c9175a3600 100644
--- a/invoice.py
+++ b/invoice.py
@@ -1,14 +1,13 @@
 # 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 decimal import Decimal
-
 from trytond.pool import PoolMeta, Pool
 from trytond.model import ModelView, Workflow, fields
 from trytond.pyson import Eval, If, Bool
 from trytond.transaction import Transaction
 from trytond.tools import grouped_slice
 
+from trytond.modules.product import round_price
+
 
 class Invoice(metaclass=PoolMeta):
     __name__ = 'account.invoice'
@@ -156,8 +155,7 @@ class InvoiceLine(metaclass=PoolMeta):
                     self.amount, agent.currency, round=False)
             amount = self._get_commission_amount(amount, plan)
             if amount:
-                digits = Commission.amount.digits
-                amount = amount.quantize(Decimal(str(10.0 ** -digits[1])))
+                amount = round_price(amount)
             if not amount:
                 continue