diff --git a/tryton/common/domain_parser.py b/tryton/common/domain_parser.py
index 25cf996f1f..f13ad814d1 100644
--- a/tryton/common/domain_parser.py
+++ b/tryton/common/domain_parser.py
@@ -177,7 +177,7 @@ def append_ending_clause(domain, clause, deep):
 def default_operator(field):
     "Return default operator for field"
     if field['type'] in ('char', 'text', 'many2one', 'many2many', 'one2many',
-            'reference'):
+            'reference', 'one2one'):
         return 'ilike'
     elif field['type'] == 'multiselection':
         return 'in'