diff --git a/CHANGES.rst b/CHANGES.rst
index 4ccac805..e65124e7 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,7 @@
+Changed
+^^^^^^^
+- Model `identifier_attributes` are fixed.
+
 [0.0.53] - 2024-04-22
 ---------------------
 
diff --git a/canaille/backends/ldap/ldapobject.py b/canaille/backends/ldap/ldapobject.py
index c40b856c..4bbbd155 100644
--- a/canaille/backends/ldap/ldapobject.py
+++ b/canaille/backends/ldap/ldapobject.py
@@ -6,7 +6,6 @@ import ldap.dn
 import ldap.filter
 from ldap.controls.readentry import PostReadControl
 
-from canaille.app import classproperty
 from canaille.backends.models import BackendModel
 
 from .backend import Backend
@@ -136,10 +135,6 @@ class LDAPObject(BackendModel, metaclass=LDAPObjectMetaclass):
             else "<LDAPOBject>"
         )
 
-    @classproperty
-    def identifier_attribute(cls):
-        return cls.rdn_attribute
-
     def __eq__(self, other):
         ldap_attributes = self.may() + self.must()
 
diff --git a/canaille/backends/ldap/models.py b/canaille/backends/ldap/models.py
index 3bd190e9..0b45bf19 100644
--- a/canaille/backends/ldap/models.py
+++ b/canaille/backends/ldap/models.py
@@ -43,10 +43,6 @@ class User(canaille.core.models.User, LDAPObject):
 
         return super().match_filter(filter)
 
-    @property
-    def identifier(self):
-        return self.rdn_value
-
     def save(self, *args, **kwargs):
         group_attr = self.python_attribute_to_ldap("groups")
         if group_attr not in self.changes:
@@ -92,10 +88,6 @@ class Group(canaille.core.models.Group, LDAPObject):
         "description": "description",
     }
 
-    @property
-    def identifier(self):
-        return self.rdn_value
-
 
 class Client(canaille.oidc.models.Client, LDAPObject):
     ldap_object_class = ["oauthClient"]
@@ -139,10 +131,6 @@ class Client(canaille.oidc.models.Client, LDAPObject):
         **client_metadata_attributes,
     }
 
-    @property
-    def identifier(self):
-        return self.rdn_value
-
 
 class AuthorizationCode(canaille.oidc.models.AuthorizationCode, LDAPObject):
     ldap_object_class = ["oauthAuthorizationCode"]
@@ -167,10 +155,6 @@ class AuthorizationCode(canaille.oidc.models.AuthorizationCode, LDAPObject):
         "revokation_date": "oauthRevokationDate",
     }
 
-    @property
-    def identifier(self):
-        return self.rdn_value
-
 
 class Token(canaille.oidc.models.Token, LDAPObject):
     ldap_object_class = ["oauthToken"]
@@ -193,10 +177,6 @@ class Token(canaille.oidc.models.Token, LDAPObject):
         "audience": "oauthAudience",
     }
 
-    @property
-    def identifier(self):
-        return self.rdn_value
-
 
 class Consent(canaille.oidc.models.Consent, LDAPObject):
     ldap_object_class = ["oauthConsent"]
@@ -213,7 +193,3 @@ class Consent(canaille.oidc.models.Consent, LDAPObject):
         "issue_date": "oauthIssueDate",
         "revokation_date": "oauthRevokationDate",
     }
-
-    @property
-    def identifier(self):
-        return self.rdn_value
diff --git a/canaille/backends/memory/models.py b/canaille/backends/memory/models.py
index 219ebb77..8c9317d0 100644
--- a/canaille/backends/memory/models.py
+++ b/canaille/backends/memory/models.py
@@ -2,7 +2,6 @@ import copy
 import datetime
 import typing
 import uuid
-from typing import ClassVar
 
 import canaille.core.models
 import canaille.oidc.models
@@ -235,30 +234,26 @@ class MemoryModel(BackendModel):
         else:
             super().__setattr__(name, value)
 
-    @property
-    def identifier(self):
-        return getattr(self, self.identifier_attribute)
-
 
 class User(canaille.core.models.User, MemoryModel):
-    identifier_attribute: ClassVar[str] = "user_name"
+    pass
 
 
 class Group(canaille.core.models.Group, MemoryModel):
-    identifier_attribute: ClassVar[str] = "display_name"
+    pass
 
 
 class Client(canaille.oidc.models.Client, MemoryModel):
-    identifier_attribute: ClassVar[str] = "client_id"
+    pass
 
 
 class AuthorizationCode(canaille.oidc.models.AuthorizationCode, MemoryModel):
-    identifier_attribute: ClassVar[str] = "authorization_code_id"
+    pass
 
 
 class Token(canaille.oidc.models.Token, MemoryModel):
-    identifier_attribute: ClassVar[str] = "token_id"
+    pass
 
 
 class Consent(canaille.oidc.models.Consent, MemoryModel):
-    identifier_attribute: ClassVar[str] = "consent_id"
+    pass
diff --git a/canaille/backends/models.py b/canaille/backends/models.py
index dbf7e98f..699b9f09 100644
--- a/canaille/backends/models.py
+++ b/canaille/backends/models.py
@@ -69,6 +69,16 @@ class Model:
             }
         return cls._attributes
 
+    @property
+    def identifier(self):
+        """Returns a unique value that will be used to identify the model
+        instance.
+
+        This value will be used in URLs in canaille, so it should be
+        unique and short.
+        """
+        return getattr(self, self.identifier_attribute)
+
 
 class BackendModel:
     """The backend model abstract class.
@@ -109,16 +119,6 @@ class BackendModel:
         return only one element or :py:data:`None` if no item is matching."""
         raise NotImplementedError()
 
-    @property
-    def identifier(self):
-        """Returns a unique value that will be used to identify the model
-        instance.
-
-        This value will be used in URLs in canaille, so it should be
-        unique and short.
-        """
-        raise NotImplementedError()
-
     def save(self):
         """Validates the current modifications in the database."""
         raise NotImplementedError()
diff --git a/canaille/backends/sql/models.py b/canaille/backends/sql/models.py
index 3fd25295..c50a7b5d 100644
--- a/canaille/backends/sql/models.py
+++ b/canaille/backends/sql/models.py
@@ -95,10 +95,6 @@ class SqlAlchemyModel(BackendModel):
             .scalar_one_or_none()
         )
 
-    @property
-    def identifier(self):
-        return getattr(self, self.identifier_attribute)
-
     def save(self):
         self.last_modified = datetime.datetime.now(datetime.timezone.utc).replace(
             microsecond=0
@@ -127,7 +123,6 @@ membership_association_table = Table(
 
 class User(canaille.core.models.User, Base, SqlAlchemyModel):
     __tablename__ = "user"
-    identifier_attribute = "user_name"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
@@ -171,7 +166,6 @@ class User(canaille.core.models.User, Base, SqlAlchemyModel):
 
 class Group(canaille.core.models.Group, Base, SqlAlchemyModel):
     __tablename__ = "group"
-    identifier_attribute = "display_name"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
@@ -200,7 +194,6 @@ client_audience_association_table = Table(
 
 class Client(canaille.oidc.models.Client, Base, SqlAlchemyModel):
     __tablename__ = "client"
-    identifier_attribute = "client_id"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
@@ -250,7 +243,6 @@ class Client(canaille.oidc.models.Client, Base, SqlAlchemyModel):
 
 class AuthorizationCode(canaille.oidc.models.AuthorizationCode, Base, SqlAlchemyModel):
     __tablename__ = "authorization_code"
-    identifier_attribute = "authorization_code_id"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
@@ -293,7 +285,6 @@ token_audience_association_table = Table(
 
 class Token(canaille.oidc.models.Token, Base, SqlAlchemyModel):
     __tablename__ = "token"
-    identifier_attribute = "token_id"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
@@ -331,7 +322,6 @@ class Token(canaille.oidc.models.Token, Base, SqlAlchemyModel):
 
 class Consent(canaille.oidc.models.Consent, Base, SqlAlchemyModel):
     __tablename__ = "consent"
-    identifier_attribute = "consent_id"
 
     id: Mapped[str] = mapped_column(
         String, primary_key=True, default=lambda: str(uuid.uuid4())
diff --git a/canaille/core/models.py b/canaille/core/models.py
index 2109e413..da0b3976 100644
--- a/canaille/core/models.py
+++ b/canaille/core/models.py
@@ -1,5 +1,6 @@
 import datetime
 from typing import Annotated
+from typing import ClassVar
 from typing import List
 from typing import Optional
 
@@ -23,6 +24,8 @@ class User(Model):
     implementation in Canaille.
     """
 
+    identifier_attribute: ClassVar[str] = "user_name"
+
     user_name: str
     """A service provider's unique identifier for the user, typically used by
     the user to directly authenticate to the service provider.
@@ -325,6 +328,8 @@ class Group(Model):
     <https://datatracker.ietf.org/doc/html/rfc7643#section-4.2>`_.
     """
 
+    identifier_attribute: ClassVar[str] = "display_name"
+
     display_name: str
     """A human-readable name for the Group.
 
diff --git a/canaille/oidc/basemodels.py b/canaille/oidc/basemodels.py
index cacb4f8c..02d25f30 100644
--- a/canaille/oidc/basemodels.py
+++ b/canaille/oidc/basemodels.py
@@ -1,4 +1,5 @@
 import datetime
+from typing import ClassVar
 from typing import List
 from typing import Optional
 
@@ -16,6 +17,8 @@ class Client(Model):
     specifications.
     """
 
+    identifier_attribute: ClassVar[str] = "client_id"
+
     description: Optional[str] = None
     preconsent: Optional[bool] = False
     audience: List["Client"] = []
@@ -288,6 +291,8 @@ class Client(Model):
 class AuthorizationCode(Model):
     """OpenID Connect temporary authorization code definition."""
 
+    identifier_attribute: ClassVar[str] = "authorization_code_id"
+
     authorization_code_id: str
     code: str
     client: "Client"
@@ -306,6 +311,8 @@ class AuthorizationCode(Model):
 class Token(Model):
     """OpenID Connect token definition."""
 
+    identifier_attribute: ClassVar[str] = "token_id"
+
     token_id: str
     access_token: str
     client: "Client"
@@ -322,6 +329,8 @@ class Token(Model):
 class Consent(Model):
     """Long-term user consent to an application."""
 
+    identifier_attribute: ClassVar[str] = "consent_id"
+
     consent_id: str
     subject: User
     client: "Client"