diff --git a/CHANGELOG b/CHANGELOG
index 68e8d6d540..840909d7de 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Set CompAux in starting balance of FEC
 * Update chart to new tax code definition
 * Allow to export FEC on draft fiscalyear
 
diff --git a/account.py b/account.py
index cbed0aa319..24fadba94c 100644
--- a/account.py
+++ b/account.py
@@ -5,6 +5,8 @@ import sys
 from io import BytesIO, StringIO
 
 from sql import Table
+from sql.aggregate import Sum
+from sql.conditionals import Coalesce
 
 from trytond.pool import PoolMeta, Pool
 from trytond.transaction import Transaction
@@ -185,33 +187,65 @@ class AccountFrFEC(Wizard):
     def get_start_balance(self):
         pool = Pool()
         Account = pool.get('account.account')
+        Move = pool.get('account.move')
+        Line = pool.get('account.move.line')
+        FiscalYear = pool.get('account.fiscalyear')
+        Period = pool.get('account.period')
+        Party = pool.get('party.party')
+        account = Account.__table__()
+        move = Move.__table__()
+        line = Line.__table__()
+        period = Period.__table__()
+        party = Party.__table__()
+        cursor = Transaction().connection.cursor()
         format_date = self.get_format_date()
         format_number = self.get_format_number()
 
-        with Transaction().set_context(
-                periods=[-1],
-                fiscalyear=self.start.fiscalyear.id,
-                posted=True,
-                cumulate=True):
-            accounts = Account.search([])
+        company = self.start.fiscalyear.company
+        fiscalyears = FiscalYear.search([
+                ('end_date', '<', self.start.fiscalyear.start_date),
+                ('company', '=', company.id),
+                ])
+        fiscalyear_ids = map(int, fiscalyears)
 
-        for account in accounts:
-            if account.credit == account.debit:
+        query = (account
+            .join(line, condition=line.account == account.id)
+            .join(move, condition=line.move == move.id)
+            .join(period, condition=move.period == period.id)
+            .join(party, 'LEFT', condition=line.party == party.id)
+            .select(
+                account.id,
+                account.code,
+                account.name,
+                party.code,
+                party.name,
+                Sum(Coalesce(line.debit, 0) - Coalesce(line.credit, 0)),
+                where=(account.company == company.id)
+                & (move.state == 'posted')
+                & (line.state != 'draft')
+                & period.fiscalyear.in_(fiscalyear_ids),
+                group_by=[
+                    account.id, account.code, account.name,
+                    party.code, party.name]))
+        cursor.execute(*query)
+        for row in cursor:
+            _, code, name, party_code, party_name, balance = row
+            if not balance:
                 continue
-            if account.debit > account.credit:
-                debit, credit = account.debit - account.credit, 0
+            if balance > 0:
+                debit, credit = balance, 0
             else:
-                debit, credit = 0, account.debit - account.credit
+                debit, credit = 0, balance
             yield [
                 self.start.deferral_journal.code
                 or self.start.deferral_journal.name,
                 self.start.deferral_journal.name,
                 self.start.deferral_post_number,
                 format_date(self.start.fiscalyear.start_date),
-                account.code,
-                account.name,
-                '',
-                '',
+                code,
+                name,
+                party_code or '',
+                party_name or '',
                 '-',
                 format_date(self.start.fiscalyear.start_date),
                 '-',
diff --git a/setup.py b/setup.py
index fb8ba03e7b..7391ab2c7b 100644
--- a/setup.py
+++ b/setup.py
@@ -53,7 +53,7 @@ for dep in info.get('depends', []):
         requires.append(get_require_version('trytond_%s' % dep))
 requires.append(get_require_version('trytond'))
 
-tests_require = [get_require_version('proteus')]
+tests_require = [get_require_version('proteus'), 'python-dateutil']
 dependency_links = []
 if minor_version % 2:
     dependency_links.append('https://trydevpi.tryton.org/')
@@ -74,7 +74,8 @@ setup(name=name,
         ],
     package_data={
         'trytond.modules.account_fr': (info.get('xml', [])
-            + ['tryton.cfg', 'view/*.xml', 'locale/*.po', 'tests/*.rst']),
+            + ['tryton.cfg', 'view/*.xml', 'locale/*.po', 'tests/*.rst',
+                'tests/FEC.csv']),
         },
     classifiers=[
         'Development Status :: 5 - Production/Stable',
diff --git a/tests/FEC.csv b/tests/FEC.csv
new file mode 100644
index 0000000000..90e136a0d7
--- /dev/null
+++ b/tests/FEC.csv
@@ -0,0 +1,5 @@
+JournalCode 	JournalLib 	EcritureNum	EcritureDate	CompteNum	CompteLib	CompAuxNum	CompAuxLib	PieceRef	PieceDate	EcritureLib	Debit	Credit	EcritureLet	DateLet	ValidDate	Montantdevise	Idevise
+Deferral	Deferral	0	20180101	797	Transferts de charges exceptionnelles			-	20180101	-	0,00	-5,00			20180101		
+Deferral	Deferral	0	20180101	4967	Autres comptes débiteurs	2	Party	-	20180101	-	5,00	0,00			20180101		
+REV	Revenue	1	20180101	797	Transferts de charges exceptionnelles			-	20180101	-	0,00	10,00			20180101		
+REV	Revenue	1	20180101	4967	Autres comptes débiteurs	2	Party	-	20180101	-	10,00	0,00			20180101		
diff --git a/tests/scenario_fec.rst b/tests/scenario_fec.rst
index 8098c0fb16..c3043c48dc 100644
--- a/tests/scenario_fec.rst
+++ b/tests/scenario_fec.rst
@@ -5,7 +5,10 @@ FEC Scenario
 Imports::
 
     >>> import datetime
+    >>> import os
+    >>> import io
     >>> from decimal import Decimal
+    >>> from dateutil.relativedelta import relativedelta
     >>> from proteus import Model, Wizard
     >>> from trytond.tests.tools import activate_modules
     >>> from trytond.modules.company.tests.tools import create_company, \
@@ -14,6 +17,8 @@ Imports::
     >>> from trytond.modules.account_fr.tests.tools import create_chart, \
     ...     get_accounts
 
+    >>> today = datetime.date(2018, 1, 1)
+
 Install account_fr::
 
     >>> config = activate_modules('account_fr')
@@ -25,9 +30,16 @@ Create company::
     >>> company.party.siren = '820043784'
     >>> company.party.save()
 
+Create last year fiscal year::
+
+    >>> fiscalyear_previous = create_fiscalyear(
+    ...     company, today=today - relativedelta(years=1))
+    >>> fiscalyear_previous.click('create_period')
+    >>> period_previous = fiscalyear_previous.periods[0]
+
 Create fiscal year::
 
-    >>> fiscalyear = create_fiscalyear(company)
+    >>> fiscalyear = create_fiscalyear(company, today=today)
     >>> fiscalyear.click('create_period')
     >>> period = fiscalyear.periods[0]
 
@@ -46,7 +58,7 @@ Create parties::
     >>> party = Party(name='Party')
     >>> party.save()
 
-Create a moves::
+Create some moves::
 
     >>> Journal = Model.get('account.journal')
     >>> Move = Model.get('account.move')
@@ -56,6 +68,22 @@ Create a moves::
     >>> journal_cash, = Journal.find([
     ...         ('code', '=', 'CASH'),
     ...         ])
+
+    >>> move = Move()
+    >>> move.period = period_previous
+    >>> move.journal = journal_revenue
+    >>> move.date = period_previous.start_date
+    >>> line = move.lines.new()
+    >>> line.account = revenue
+    >>> line.credit = Decimal(5)
+    >>> line = move.lines.new()
+    >>> line.account = receivable
+    >>> line.debit = Decimal(5)
+    >>> line.party = party
+    >>> move.post_date = period_previous.start_date
+    >>> move.post_number = '1'
+    >>> move.click('post')
+
     >>> move = Move()
     >>> move.period = period
     >>> move.journal = journal_revenue
@@ -67,6 +95,8 @@ Create a moves::
     >>> line.account = receivable
     >>> line.debit = Decimal(10)
     >>> line.party = party
+    >>> move.post_date = period.start_date
+    >>> move.post_number = '1'
     >>> move.click('post')
 
 Generate FEC::
@@ -80,5 +110,6 @@ Generate FEC::
     >>> FEC.form.deferral_journal = deferral_journal
     >>> FEC.execute('generate')
     >>> FEC.form.filename
-    >>> bool(FEC.form.file)
+    >>> file = os.path.join(os.path.dirname(__file__), 'FEC.csv')
+    >>> FEC.form.file.decode('utf-8') == io.open(file, mode='rb').read().decode('utf-8')
     True