diff --git a/sao/src/common.js b/sao/src/common.js
index 0ff060c6bb..9accc69fac 100644
--- a/sao/src/common.js
+++ b/sao/src/common.js
@@ -1204,11 +1204,12 @@
                 var name = clause[0];
                 var operator = clause[1];
                 var value = clause[2];
-                if (name.endsWith('.rec_name')) {
+                if (name.endsWith('.rec_name')
+                    && (value || (clause.length > 3))) {
                     name = name.slice(0, -9);
                 }
                 if (!(name in this.fields)) {
-                    if (this.is_full_text(value)) {
+                    if ((value !== null) && this.is_full_text(value)) {
                         value = value.slice(1, -1);
                     }
                     return this.quote(value);
@@ -2149,7 +2150,7 @@
                         break;
                     }
                 }
-                return target + ',' + value;
+                return target + ',' + (value || '');
             };
 
             var converts = {
diff --git a/sao/tests/sao.js b/sao/tests/sao.js
index ec3c5b3fa5..8ad1265bea 100644
--- a/sao/tests/sao.js
+++ b/sao/tests/sao.js
@@ -1930,6 +1930,9 @@
         [[c(['Reference', null, 'Spam,bar'])], [
             c(['reference.rec_name', 'ilike', '%bar%', 'spam'])
             ]],
+        [[c(['Reference', null, 'Spam,'])], [
+            c(['reference.rec_name', 'ilike', '%', 'spam'])
+            ]],
         [[c(['Reference', null, ['foo', 'bar']])], [
             c(['reference', 'in', ['foo', 'bar']])
             ]],
@@ -2250,6 +2253,7 @@
         [[['multiselection', 'not in', ['foo', 'bar']]], "MultiSelection: !Foo;Bar"],
         [[['reference', 'ilike', '%foo%']], 'Reference: foo'],
         [[['reference', 'ilike', '%bar%', 'spam']], 'Reference: Spam,bar'],
+        [[['reference.rec_name', '=', null, 'spam']], 'Reference: =Spam,'],
         [[['reference', 'in', ['foo', 'bar']]], 'Reference: foo;bar'],
         [[['many2one', 'ilike', '%John%']], 'Many2One: John'],
         [[['many2one.rec_name', 'in', ['John', 'Jane']]], 'Many2One: John;Jane'],
diff --git a/tryton/tryton/common/domain_parser.py b/tryton/tryton/common/domain_parser.py
index df46a1c3a8..030066282c 100644
--- a/tryton/tryton/common/domain_parser.py
+++ b/tryton/tryton/common/domain_parser.py
@@ -361,7 +361,7 @@ def format_value(field, value, target=None, context=None, _quote_empty=False):
         if not target:
             return format_selection()
         selections = dict(field['selection'])
-        return '%s,%s' % (selections.get(target, target), value)
+        return '%s,%s' % (selections.get(target, target), value or '')
 
     def format_datetime():
         if not value:
@@ -617,10 +617,11 @@ class DomainParser(object):
                     or clause[0] in ('AND', 'OR')):
                 return '(%s)' % self.string(clause)
             name, operator, value = clause[:3]
-            if name.endswith('.rec_name'):
+            if (name.endswith('.rec_name')
+                    and (value or len(clause) > 3)):
                 name = name[:-9]
             if name not in self.fields:
-                if is_full_text(value):
+                if value is not None and is_full_text(value):
                     value = value[1:-1]
                 return quote(value)
             field = self.fields[name]
diff --git a/tryton/tryton/tests/test_common_domain_parser.py b/tryton/tryton/tests/test_common_domain_parser.py
index 26e98d2ac2..5b21c2d6f3 100644
--- a/tryton/tryton/tests/test_common_domain_parser.py
+++ b/tryton/tryton/tests/test_common_domain_parser.py
@@ -768,6 +768,9 @@ class DomainParserTestCase(TestCase):
         self.assertEqual(
             dom.string([('reference.rec_name', 'ilike', '%bar%', 'spam')]),
             'Reference: Spam,bar')
+        self.assertEqual(
+            dom.string([('reference.rec_name', '=', None, 'spam')]),
+            "Reference: =Spam,")
         self.assertEqual(
             dom.string([('reference', 'in', ['foo', 'bar'])]),
             'Reference: foo;bar')
@@ -1081,6 +1084,10 @@ class DomainParserTestCase(TestCase):
             rlist(dom.parse_clause([('Reference', None, 'Spam,bar')])), [
                 ('reference.rec_name', 'ilike', '%bar%', 'spam'),
                 ])
+        self.assertEqual(
+            rlist(dom.parse_clause([('Reference', None, 'Spam,')])), [
+                ('reference.rec_name', 'ilike', '%', 'spam'),
+                ])
         self.assertEqual(
             rlist(dom.parse_clause([('Reference', None, ['foo', 'bar'])])), [
                 ('reference', 'in', ['foo', 'bar']),