diff --git a/odoo/addons/base/tests/test_expression.py b/odoo/addons/base/tests/test_expression.py
index 505194ff64f..2c10677ef2e 100644
--- a/odoo/addons/base/tests/test_expression.py
+++ b/odoo/addons/base/tests/test_expression.py
@@ -704,6 +704,10 @@ class TestExpression(SavepointCaseWithUserDemo):
             countries = self._search(Country, domain)
             self.assertEqual(countries, belgium)
 
+        countries = self._search(Country, [('name', 'not in', ['No country'])])
+        all_countries = self._search(Country, [])
+        self.assertEqual(countries, all_countries)
+
     @mute_logger('odoo.sql_db')
     def test_invalid(self):
         """ verify that invalid expressions are refused, even for magic fields """
diff --git a/odoo/osv/expression.py b/odoo/osv/expression.py
index ce819013d02..a6ee9cf059e 100644
--- a/odoo/osv/expression.py
+++ b/odoo/osv/expression.py
@@ -909,7 +909,7 @@ class expression(object):
                     sql_operator = {'=like': 'like', '=ilike': 'ilike'}.get(operator, operator)
                     if need_wildcard:
                         right = '%%%s%%' % right
-                    if sql_operator == 'in':
+                    if sql_operator in ('in', 'not in'):
                         right = tuple(right)
 
                     unaccent = self._unaccent if sql_operator.endswith('like') else lambda x: x