diff --git a/zoo/zoo_data/lookups.py b/zoo/zoo_data/lookups.py
index 7693de3..cf01358 100644
--- a/zoo/zoo_data/lookups.py
+++ b/zoo/zoo_data/lookups.py
@@ -16,87 +16,40 @@
 
 import django
 
-from django.db.models import Transform, TextField, DateField
+from django.db.models import Transform, CharField, DateField
+from django.db.models.functions import Lower
 
 from django.contrib.postgres.fields import jsonb
 try:
-    from django.contrib.postgres.fields.jsonb import KeyTransform, KeyTransformTextLookupMixin
+    from django.db.models.fields.json import KeyTransform, KeyTransformTextLookupMixin
 except ImportError:
-    # backport from Django 2.x
-    class KeyTransform(Transform):
-        operator = '->'
-        nested_operator = '#>'
-
-        def __init__(self, key_name, *args, **kwargs):
-            super(KeyTransform, self).__init__(*args, **kwargs)
-            self.key_name = key_name
-
-        def as_sql(self, compiler, connection):
-            key_transforms = [self.key_name]
-            previous = self.lhs
-            while isinstance(previous, KeyTransform):
-                key_transforms.insert(0, previous.key_name)
-                previous = previous.lhs
-            lhs, params = compiler.compile(previous)
-            if len(key_transforms) > 1:
-                return "(%s %s %%s)" % (lhs, self.nested_operator), [key_transforms] + params
-            try:
-                int(self.key_name)
-            except ValueError:
-                lookup = "'%s'" % self.key_name
-            else:
-                lookup = "%s" % self.key_name
-            return "(%s %s %s)" % (lhs, self.operator, lookup), params
-
-    jsonb.KeyTransform = KeyTransform
-
-    class KeyTextTransform(KeyTransform):
-        operator = '->>'
-        nested_operator = '#>>'
-        _output_field = TextField()
-
-    class KeyTransformTextLookupMixin(object):
-        """
-        Mixin for combining with a lookup expecting a text lhs from a JSONField
-        key lookup. Make use of the ->> operator instead of casting key values to
-        text and performing the lookup on the resulting representation.
-        """
-        def __init__(self, key_transform, *args, **kwargs):
-            assert isinstance(key_transform, KeyTransform)
-            key_text_transform = KeyTextTransform(
-                key_transform.key_name, *key_transform.source_expressions, **key_transform.extra
-            )
-            super(KeyTransformTextLookupMixin, self).__init__(key_text_transform, *args, **kwargs)
-
-
-class Lower(Transform):
-    lookup_name = 'lower'
-    function = 'LOWER'
-
-TextField.register_lookup(Lower)
+    from django.contrib.postgres.fields.jsonb import KeyTransform, KeyTransformTextLookupMixin
 
 
 class Unaccent(Transform):
     lookup_name = 'unaccent'
     function = 'immutable_unaccent'
+    output_field = CharField()
 
-TextField.register_lookup(Unaccent)
+CharField.register_lookup(Unaccent)
 
+CharField.register_lookup(Lower)
 
 class Normalize(Transform):
     lookup_name = 'normalize'
     function = 'immutable_normalize'
+    output_field = CharField()
 
-TextField.register_lookup(Normalize)
+CharField.register_lookup(Normalize)
 
 
 class Date(Transform):
     lookup_name = 'timestamp'
     function = 'immutable_date'
-    _output_field = DateField()
+    output_field = DateField()
 
 
-TextField.register_lookup(Date)
+CharField.register_lookup(Date)
 
 
 class JSONUnaccent(KeyTransformTextLookupMixin, Unaccent):
diff --git a/zoo/zoo_data/models.py b/zoo/zoo_data/models.py
index 2c02446..cf4c58a 100644
--- a/zoo/zoo_data/models.py
+++ b/zoo/zoo_data/models.py
@@ -24,6 +24,7 @@ import datetime
 
 from django.db import models, connection
 from django.db.models import F, Value
+from django.db.models.functions import Lower
 from django.db.models.query import QuerySet, Q
 from django.core.exceptions import ValidationError
 from django.urls import reverse
@@ -33,7 +34,7 @@ from django.contrib.postgres.fields import JSONField
 from django.contrib.postgres.search import TrigramDistance
 
 
-from .search import Unaccent, Lower, JSONTextRef
+from .search import Unaccent, JSONTextRef
 from zoo.zoo_meta.validators import schema_validator
 
 
@@ -74,7 +75,7 @@ class EntityQuerySet(QuerySet):
         for key, value in kwargs.items():
             filters.append(Q(**{
                 'content__' + key + '__unaccent__lower__trigram_similar':
-                Lower(Unaccent(Value(value))),
+                Unaccent(Lower(Value(value))),
             }))
         qs = qs.filter(functools.reduce(__or__, filters))
         expressions = []
diff --git a/zoo/zoo_data/search.py b/zoo/zoo_data/search.py
index c7dc555..f5ee6a1 100644
--- a/zoo/zoo_data/search.py
+++ b/zoo/zoo_data/search.py
@@ -14,7 +14,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-from django.db.models import Func, Value
+from django.db.models import Func, Value, CharField
 
 
 class Unaccent(Func):
@@ -27,11 +27,6 @@ class Normalize(Func):
     arity = 1
 
 
-class Lower(Func):
-    function = 'LOWER'
-    arity = 1
-
-
 class JSONRef(Func):
     function = ''
     arg_joiner = '->'
@@ -46,6 +41,7 @@ class JSONTextRef(Func):
     function = ''
     arg_joiner = '->>'
     arity = 2
+    output_field = CharField()
 
     def __init__(self, *expressions, **extra):
         jsonb = expressions[0]
diff --git a/zoo/zoo_nanterre/utils.py b/zoo/zoo_nanterre/utils.py
index a0d338a..35405ed 100644
--- a/zoo/zoo_nanterre/utils.py
+++ b/zoo/zoo_nanterre/utils.py
@@ -38,7 +38,7 @@ import psycopg2
 from django.conf import settings
 from django.contrib.postgres.search import TrigramDistance
 from django.db import connection
-from django.db.models import Q, F, Value, ExpressionWrapper, CharField, When, Case
+from django.db.models import Q, F, Value, ExpressionWrapper, CharField, When, Case, CharField
 from django.db.models.functions import Least, Greatest, Coalesce, Concat
 from django.db import transaction
 from django.contrib.auth.hashers import make_password
@@ -541,7 +541,7 @@ class PersonSearch(object):
                 Coalesce(
                     JSONTextRef(F('content'), 'nom_d_usage'),
                     JSONTextRef(F('content'), 'nom_de_naissance'),
-                    Value(' ')
+                    Value(' '),
                 ),
                 Value(' '),
                 JSONTextRef(F('content'), 'prenoms'))