diff --git a/complaint.py b/complaint.py
index deaca12cae..a48b1af178 100644
--- a/complaint.py
+++ b/complaint.py
@@ -150,13 +150,13 @@ class Complaint(Workflow, ModelSQL, ModelView):
             'account.invoice': [
                 ('party', '=', Eval('customer')),
                 ('company', '=', Eval('company')),
-                ('type', '=', 'out_invoice'),
+                ('type', '=', 'out'),
                 ('state', 'in', ['posted', 'paid']),
                 ],
             'account.invoice.line': [
                 ('invoice.party', '=', Eval('customer')),
                 ('invoice.company', '=', Eval('company')),
-                ('invoice.type', '=', 'out_invoice'),
+                ('invoice.type', '=', 'out'),
                 ('invoice.state', 'in', ['posted', 'paid']),
                 ],
             }
@@ -434,7 +434,7 @@ class Action(ModelSQL, ModelView):
                 credit_line['origin'] = str(self.complaint)
             if isinstance(self.complaint.origin, Line):
                 if self.quantity is not None:
-                    lines_values[0]['quantity'] = self.quantity
+                    lines_values[0]['quantity'] = -self.quantity
                 if self.unit_price is not None:
                     lines_values[0]['unit_price'] = self.unit_price
             values['lines'] = [('create', lines_values)]
diff --git a/tests/scenario_sale_complaint.rst b/tests/scenario_sale_complaint.rst
index 807fea27bc..119bbc6e27 100644
--- a/tests/scenario_sale_complaint.rst
+++ b/tests/scenario_sale_complaint.rst
@@ -186,11 +186,11 @@ Create a complaint to credit the invoice::
     >>> action, = complaint.actions
     >>> credit_note = action.result
     >>> credit_note.type
-    u'out_credit_note'
+    u'out'
     >>> len(credit_note.lines)
     2
     >>> sum(l.quantity for l in credit_note.lines)
-    5.0
+    -5.0
 
 Create a complaint to credit a invoice line::
 
@@ -209,7 +209,7 @@ Create a complaint to credit a invoice line::
     >>> action, = complaint.actions
     >>> credit_note = action.result
     >>> credit_note.type
-    u'out_credit_note'
+    u'out'
     >>> credit_note_line, = credit_note.lines
     >>> credit_note_line.quantity
-    1.0
+    -1.0