diff --git a/stock.py b/stock.py
index 978feee6ad..72eab2f0a2 100644
--- a/stock.py
+++ b/stock.py
@@ -28,41 +28,34 @@ class Move(ModelSQL, ModelView):
         lines = super(Move, self)._get_account_stock_move_lines(move, type_)
         if (type_.endswith('supplier')
                 and move.product.cost_price_method == 'fixed'):
-            move_line = {
-                'name': move.rec_name,
-                }
             cost_price = uom_obj.compute_price(move.product.default_uom,
                 move.cost_price, move.uom)
             amount = currency_obj.round(move.company.currency,
                 Decimal(str(move.quantity)) * (move.unit_price - cost_price))
             if currency_obj.is_zero(move.company.currency, amount):
                 return lines
+            account_id = move.product.account_stock_supplier_used.id
+            for move_line in lines:
+                if move_line['account'] == account_id:
+                    break
+            else:
+                return lines
             if type_.startswith('in_'):
-                if amount > Decimal(0):
-                    move_line['debit'] = Decimal(0)
-                    move_line['credit'] = amount
-                else:
-                    move_line['debit'] = -amount
-                    move_line['credit'] = Decimal(0)
-                account_type = type_[3:]
+                move_line['credit'] += amount
+                debit = amount
+                credit = Decimal(0)
             else:
-                if amount > Decimal(0):
-                    move_line['debit'] = amount
-                    move_line['credit'] = Decimal(0)
-                else:
-                    move_line['debit'] = Decimal(0)
-                    move_line['credit'] = -amount
-                account_type = type_[4:]
-            move_line['account'] = getattr(move.product,
-                'account_stock_%s_used' % account_type).id
-            lines.append(move_line)
-            move_line = move_line.copy()
-            move_line['debit'], move_line['credit'] = \
-                move_line['credit'], move_line['debit']
-            if account_type == 'supplier':
-                move_line['account'] = move.product.account_expense_used.id
-            else:
-                move_line['account'] = move.product.account_revenue_used.id
+                move_line['debit'] += amount
+                debit = Decimal(0)
+                credit = amount
+            if amount < Decimal(0):
+                debit, credit = -credit, -debit
+            move_line = {
+                'name': move.rec_name,
+                'debit': debit,
+                'credit': credit,
+                'account': move.product.account_expense_used.id,
+                }
             lines.append(move_line)
         return lines
 
diff --git a/tests/scenario_account_stock_anglo_saxon.rst b/tests/scenario_account_stock_anglo_saxon.rst
index 41ae661e6f..bbfdb18ae7 100644
--- a/tests/scenario_account_stock_anglo_saxon.rst
+++ b/tests/scenario_account_stock_anglo_saxon.rst
@@ -223,8 +223,9 @@ Receive 9 products::
     >>> shipment.state
     u'done'
     >>> stock_supplier.reload()
+    >>> stock.reload()
     >>> (stock_supplier.debit, stock_supplier.credit) == \
-    ... (Decimal('4.00'), Decimal('50.00'))
+    ... (Decimal('0.00'), Decimal('46.00'))
     True
     >>> stock.reload()
     >>> (stock.debit, stock.credit) == \
@@ -258,7 +259,7 @@ Open supplier invoice::
     True
     >>> stock_supplier.reload()
     >>> (stock_supplier.debit, stock_supplier.credit) == \
-    ... (Decimal('50.00'), Decimal('50.00'))
+    ... (Decimal('46.00'), Decimal('46.00'))
     True
 
 Sale 5 products::