diff --git a/bin/osv/expression.py b/bin/osv/expression.py
index cb1280c8e3b..3281fd29f7c 100644
--- a/bin/osv/expression.py
+++ b/bin/osv/expression.py
@@ -185,7 +185,7 @@ class expression(object):
                 else:
                     call_null = True
 
-                    if right:
+                    if right is not False:
                         if isinstance(right, basestring):
                             ids2 = [x[0] for x in field_obj.name_search(cr, uid, right, [], operator, context=context, limit=None)]
                             if ids2:
@@ -234,7 +234,7 @@ class expression(object):
                     self.__exp[i] = ('id', 'in', _rec_convert(ids2))
                 else:
                     call_null_m2m = True
-                    if right:
+                    if right is not False:
                         if isinstance(right, basestring):
                             res_ids = [x[0] for x in field_obj.name_search(cr, uid, right, [], operator, context=context)]
                             if res_ids: