diff --git a/canaille/backends/__init__.py b/canaille/backends/__init__.py
index a7bfcad1..dba168c2 100644
--- a/canaille/backends/__init__.py
+++ b/canaille/backends/__init__.py
@@ -85,6 +85,10 @@ class BaseBackend:
         only one element or :py:data:`None` if no item is matching."""
         raise NotImplementedError()
 
+    def save(self, instance):
+        """Validate the current modifications in the database."""
+        raise NotImplementedError()
+
     def check_user_password(self, user, password: str) -> bool:
         """Check if the password matches the user password in the database."""
         raise NotImplementedError()
diff --git a/canaille/backends/ldap/backend.py b/canaille/backends/ldap/backend.py
index e48f51e1..44c893a4 100644
--- a/canaille/backends/ldap/backend.py
+++ b/canaille/backends/ldap/backend.py
@@ -9,6 +9,7 @@ from flask import current_app
 from ldap.controls import DecodeControlTuples
 from ldap.controls.ppolicy import PasswordPolicyControl
 from ldap.controls.ppolicy import PasswordPolicyError
+from ldap.controls.readentry import PostReadControl
 
 from canaille.app import models
 from canaille.app.configuration import ConfigurationException
@@ -128,7 +129,7 @@ class Backend(BaseBackend):
                     emails=f"canaille_{uuid.uuid4()}@mydomain.tld",
                     password="correct horse battery staple",
                 )
-                user.save()
+                BaseBackend.instance.save(user)
                 user.delete()
 
             except ldap.INSUFFICIENT_ACCESS as exc:
@@ -147,13 +148,13 @@ class Backend(BaseBackend):
                     emails=f"canaille_{uuid.uuid4()}@mydomain.tld",
                     password="correct horse battery staple",
                 )
-                user.save()
+                BaseBackend.instance.save(user)
 
                 group = models.Group(
                     display_name=f"canaille_{uuid.uuid4()}",
                     members=[user],
                 )
-                group.save()
+                BaseBackend.instance.save(group)
                 group.delete()
 
             except ldap.INSUFFICIENT_ACCESS as exc:
@@ -324,6 +325,69 @@ class Backend(BaseBackend):
 
             return None
 
+    def save(self, instance):
+        # run the instance save callback if existing
+        save_callback = instance.save() if hasattr(instance, "save") else iter([])
+        next(save_callback, None)
+
+        current_object_classes = instance.get_ldap_attribute("objectClass") or []
+        instance.set_ldap_attribute(
+            "objectClass",
+            list(set(instance.ldap_object_class) | set(current_object_classes)),
+        )
+
+        # PostReadControl allows to read the updated object attributes on creation/edition
+        attributes = ["objectClass"] + [
+            instance.python_attribute_to_ldap(name) for name in instance.attributes
+        ]
+        read_post_control = PostReadControl(criticality=True, attrList=attributes)
+
+        # Object already exists in the LDAP database
+        if instance.exists:
+            deletions = [
+                name
+                for name, value in instance.changes.items()
+                if (
+                    value is None
+                    or value == []
+                    or (isinstance(value, list) and len(value) == 1 and not value[0])
+                )
+                and name in instance.state
+            ]
+            changes = {
+                name: value
+                for name, value in instance.changes.items()
+                if name not in deletions and instance.state.get(name) != value
+            }
+            formatted_changes = python_attrs_to_ldap(changes, null_allowed=False)
+            modlist = [(ldap.MOD_DELETE, name, None) for name in deletions] + [
+                (ldap.MOD_REPLACE, name, values)
+                for name, values in formatted_changes.items()
+            ]
+            _, _, _, [result] = self.connection.modify_ext_s(
+                instance.dn, modlist, serverctrls=[read_post_control]
+            )
+
+        # Object does not exist yet in the LDAP database
+        else:
+            changes = {
+                name: value
+                for name, value in {**instance.state, **instance.changes}.items()
+                if value and value[0]
+            }
+            formatted_changes = python_attrs_to_ldap(changes, null_allowed=False)
+            modlist = [(name, values) for name, values in formatted_changes.items()]
+            _, _, _, [result] = self.connection.add_ext_s(
+                instance.dn, modlist, serverctrls=[read_post_control]
+            )
+
+        instance.exists = True
+        instance.state = {**result.entry, **instance.changes}
+        instance.changes = {}
+
+        # run the instance save callback again if existing
+        next(save_callback, None)
+
 
 def setup_ldap_models(config):
     from canaille.app import models
diff --git a/canaille/backends/ldap/ldapobject.py b/canaille/backends/ldap/ldapobject.py
index 2eacee7b..2955a0da 100644
--- a/canaille/backends/ldap/ldapobject.py
+++ b/canaille/backends/ldap/ldapobject.py
@@ -2,7 +2,6 @@ import typing
 
 import ldap.dn
 import ldap.filter
-from ldap.controls.readentry import PostReadControl
 
 from canaille.backends.models import BackendModel
 
@@ -264,64 +263,6 @@ class LDAPObject(BackendModel, metaclass=LDAPObjectMetaclass):
         self.changes = {}
         self.state = result[0][1]
 
-    def save(self):
-        conn = Backend.instance.connection
-
-        current_object_classes = self.get_ldap_attribute("objectClass") or []
-        self.set_ldap_attribute(
-            "objectClass",
-            list(set(self.ldap_object_class) | set(current_object_classes)),
-        )
-
-        # PostReadControl allows to read the updated object attributes on creation/edition
-        attributes = ["objectClass"] + [
-            self.python_attribute_to_ldap(name) for name in self.attributes
-        ]
-        read_post_control = PostReadControl(criticality=True, attrList=attributes)
-
-        # Object already exists in the LDAP database
-        if self.exists:
-            deletions = [
-                name
-                for name, value in self.changes.items()
-                if (
-                    value is None
-                    or value == []
-                    or (isinstance(value, list) and len(value) == 1 and not value[0])
-                )
-                and name in self.state
-            ]
-            changes = {
-                name: value
-                for name, value in self.changes.items()
-                if name not in deletions and self.state.get(name) != value
-            }
-            formatted_changes = python_attrs_to_ldap(changes, null_allowed=False)
-            modlist = [(ldap.MOD_DELETE, name, None) for name in deletions] + [
-                (ldap.MOD_REPLACE, name, values)
-                for name, values in formatted_changes.items()
-            ]
-            _, _, _, [result] = conn.modify_ext_s(
-                self.dn, modlist, serverctrls=[read_post_control]
-            )
-
-        # Object does not exist yet in the LDAP database
-        else:
-            changes = {
-                name: value
-                for name, value in {**self.state, **self.changes}.items()
-                if value and value[0]
-            }
-            formatted_changes = python_attrs_to_ldap(changes, null_allowed=False)
-            modlist = [(name, values) for name, values in formatted_changes.items()]
-            _, _, _, [result] = conn.add_ext_s(
-                self.dn, modlist, serverctrls=[read_post_control]
-            )
-
-        self.exists = True
-        self.state = {**result.entry, **self.changes}
-        self.changes = {}
-
     def delete(self):
         conn = Backend.instance.connection
         try:
diff --git a/canaille/backends/ldap/models.py b/canaille/backends/ldap/models.py
index c931ffcc..c4e99a3d 100644
--- a/canaille/backends/ldap/models.py
+++ b/canaille/backends/ldap/models.py
@@ -43,10 +43,10 @@ class User(canaille.core.models.User, LDAPObject):
 
         return super().match_filter(filter)
 
-    def save(self, *args, **kwargs):
+    def save(self):
         group_attr = self.python_attribute_to_ldap("groups")
         if group_attr not in self.changes:
-            return super().save(*args, **kwargs)
+            return
 
         # The LDAP attribute memberOf cannot directly be edited,
         # so this is needed to update the Group.member attribute
@@ -60,11 +60,11 @@ class User(canaille.core.models.User, LDAPObject):
         to_del = set(old_groups) - set(new_groups)
         del self.changes[group_attr]
 
-        super().save(*args, **kwargs)
+        yield
 
         for group in to_add:
             group.members = group.members + [self]
-            group.save()
+            Backend.instance.save(group)
 
         for group in to_del:
             # LDAP groups cannot be empty because groupOfNames.member
@@ -73,7 +73,7 @@ class User(canaille.core.models.User, LDAPObject):
             # TODO: properly manage the situation where one wants to
             # remove the last member of a group
             group.members = [member for member in group.members if member != self]
-            group.save()
+            Backend.instance.save(group)
 
         self.state[group_attr] = new_groups
 
diff --git a/canaille/backends/memory/backend.py b/canaille/backends/memory/backend.py
index fbeb3020..038bb0e2 100644
--- a/canaille/backends/memory/backend.py
+++ b/canaille/backends/memory/backend.py
@@ -1,3 +1,6 @@
+import datetime
+import uuid
+
 from canaille.backends import BaseBackend
 
 
@@ -39,7 +42,7 @@ class Backend(BaseBackend):
 
     def set_user_password(self, user, password):
         user.password = password
-        user.save()
+        self.save(user)
 
     def query(self, model, **kwargs):
         # if there is no filter, return all models
@@ -91,3 +94,17 @@ class Backend(BaseBackend):
 
         results = self.query(model, **kwargs)
         return results[0] if results else None
+
+    def save(self, instance):
+        if not instance.id:
+            instance.id = str(uuid.uuid4())
+
+        instance.last_modified = datetime.datetime.now(datetime.timezone.utc).replace(
+            microsecond=0
+        )
+        if not instance.created:
+            instance.created = instance.last_modified
+
+        instance.index_delete()
+        instance.index_save()
+        instance._cache = {}
diff --git a/canaille/backends/memory/models.py b/canaille/backends/memory/models.py
index 41ebb8ce..cc2cc33e 100644
--- a/canaille/backends/memory/models.py
+++ b/canaille/backends/memory/models.py
@@ -1,7 +1,5 @@
 import copy
-import datetime
 import typing
-import uuid
 
 import canaille.core.models
 import canaille.oidc.models
@@ -67,20 +65,6 @@ class MemoryModel(BackendModel):
 
         return value
 
-    def save(self):
-        if not self.id:
-            self.id = str(uuid.uuid4())
-
-        self.last_modified = datetime.datetime.now(datetime.timezone.utc).replace(
-            microsecond=0
-        )
-        if not self.created:
-            self.created = self.last_modified
-
-        self.index_delete()
-        self.index_save()
-        self._cache = {}
-
     def delete(self):
         self.index_delete()
 
diff --git a/canaille/backends/models.py b/canaille/backends/models.py
index 3e8998b6..b07da30e 100644
--- a/canaille/backends/models.py
+++ b/canaille/backends/models.py
@@ -88,10 +88,6 @@ class BackendModel:
     implemented for every model and for every backend.
     """
 
-    def save(self):
-        """Validate the current modifications in the database."""
-        raise NotImplementedError()
-
     def delete(self):
         """Remove the current instance from the database."""
         raise NotImplementedError()
diff --git a/canaille/backends/sql/backend.py b/canaille/backends/sql/backend.py
index 39866386..4f8ecaf0 100644
--- a/canaille/backends/sql/backend.py
+++ b/canaille/backends/sql/backend.py
@@ -1,3 +1,5 @@
+import datetime
+
 from sqlalchemy import create_engine
 from sqlalchemy import or_
 from sqlalchemy import select
@@ -66,7 +68,7 @@ class Backend(BaseBackend):
 
     def set_user_password(self, user, password):
         user.password = password
-        user.save()
+        self.save(user)
 
     def query(self, model, **kwargs):
         filter = [
@@ -106,3 +108,13 @@ class Backend(BaseBackend):
         return Backend.instance.db_session.execute(
             select(model).filter(*filter)
         ).scalar_one_or_none()
+
+    def save(self, instance):
+        instance.last_modified = datetime.datetime.now(datetime.timezone.utc).replace(
+            microsecond=0
+        )
+        if not instance.created:
+            instance.created = instance.last_modified
+
+        Backend.instance.db_session.add(instance)
+        Backend.instance.db_session.commit()
diff --git a/canaille/backends/sql/models.py b/canaille/backends/sql/models.py
index bd14f85a..302f4d37 100644
--- a/canaille/backends/sql/models.py
+++ b/canaille/backends/sql/models.py
@@ -47,16 +47,6 @@ class SqlAlchemyModel(BackendModel):
 
         return getattr(cls, name) == value
 
-    def save(self):
-        self.last_modified = datetime.datetime.now(datetime.timezone.utc).replace(
-            microsecond=0
-        )
-        if not self.created:
-            self.created = self.last_modified
-
-        Backend.instance.db_session.add(self)
-        Backend.instance.db_session.commit()
-
     def delete(self):
         Backend.instance.db_session.delete(self)
         Backend.instance.db_session.commit()
diff --git a/canaille/core/endpoints/account.py b/canaille/core/endpoints/account.py
index a34af0da..fd74436e 100644
--- a/canaille/core/endpoints/account.py
+++ b/canaille/core/endpoints/account.py
@@ -404,7 +404,7 @@ def email_confirmation(data, hash):
         return redirect(url_for("core.account.index"))
 
     user.emails = user.emails + [confirmation_obj.email]
-    user.save()
+    BaseBackend.instance.save(user)
     flash(_("Your email address have been confirmed."), "success")
     return redirect(url_for("core.account.index"))
 
@@ -460,11 +460,11 @@ def profile_create(current_app, form):
     given_name = user.given_name if user.given_name else ""
     family_name = user.family_name if user.family_name else ""
     user.formatted_name = f"{given_name} {family_name}".strip()
-    user.save()
+    BaseBackend.instance.save(user)
 
     if form["password1"].data:
         BaseBackend.instance.set_user_password(user, form["password1"].data)
-        user.save()
+        BaseBackend.instance.save(user)
 
     return user
 
@@ -536,7 +536,7 @@ def profile_edition_main_form_validation(user, edited_user, profile_form):
         if profile_form["preferred_language"].data == "auto":
             edited_user.preferred_language = None
 
-    edited_user.save()
+    BaseBackend.instance.save(edited_user)
     g.user.reload()
 
 
@@ -574,7 +574,7 @@ def profile_edition_remove_email(user, edited_user, email):
         return False
 
     edited_user.emails = [m for m in edited_user.emails if m != email]
-    edited_user.save()
+    BaseBackend.instance.save(edited_user)
     return True
 
 
@@ -730,7 +730,7 @@ def profile_settings(user, edited_user):
     ):
         flash(_("The account has been locked"), "success")
         edited_user.lock_date = datetime.datetime.now(datetime.timezone.utc)
-        edited_user.save()
+        BaseBackend.instance.save(edited_user)
 
         return profile_settings_edit(user, edited_user)
 
@@ -741,7 +741,7 @@ def profile_settings(user, edited_user):
     ):
         flash(_("The account has been unlocked"), "success")
         edited_user.lock_date = None
-        edited_user.save()
+        BaseBackend.instance.save(edited_user)
 
         return profile_settings_edit(user, edited_user)
 
@@ -791,7 +791,7 @@ def profile_settings_edit(editor, edited_user):
                     edited_user, form["password1"].data
                 )
 
-            edited_user.save()
+            BaseBackend.instance.save(edited_user)
             flash(_("Profile updated successfully."), "success")
             return redirect(
                 url_for("core.account.profile_settings", edited_user=edited_user)
diff --git a/canaille/core/endpoints/groups.py b/canaille/core/endpoints/groups.py
index 3aeeb3a6..3edad29c 100644
--- a/canaille/core/endpoints/groups.py
+++ b/canaille/core/endpoints/groups.py
@@ -11,6 +11,7 @@ from canaille.app.flask import render_htmx_template
 from canaille.app.forms import TableForm
 from canaille.app.i18n import gettext as _
 from canaille.app.themes import render_template
+from canaille.backends import BaseBackend
 
 from .forms import CreateGroupForm
 from .forms import DeleteGroupMemberForm
@@ -42,7 +43,7 @@ def create_group(user):
             group.members = [user]
             group.display_name = form.display_name.data
             group.description = form.description.data
-            group.save()
+            BaseBackend.instance.save(group)
             flash(
                 _(
                     "The group %(group)s has been sucessfully created",
@@ -102,7 +103,7 @@ def edit_group(group):
     ):
         if form.validate():
             group.description = form.description.data
-            group.save()
+            BaseBackend.instance.save(group)
             flash(
                 _(
                     "The group %(group)s has been sucessfully edited.",
@@ -151,7 +152,7 @@ def delete_member(group):
         group.members = [
             member for member in group.members if member != form.member.data
         ]
-        group.save()
+        BaseBackend.instance.save(group)
 
     return edit_group(group)
 
diff --git a/canaille/core/populate.py b/canaille/core/populate.py
index dbba5195..7dd0e9ec 100644
--- a/canaille/core/populate.py
+++ b/canaille/core/populate.py
@@ -40,7 +40,7 @@ def fake_users(nb=1):
                 password=fake.password(),
                 preferred_language=fake._locales[0],
             )
-            user.save()
+            BaseBackend.instance.save(user)
             users.append(user)
         except Exception:  # pragma: no cover
             pass
@@ -59,7 +59,7 @@ def fake_groups(nb=1, nb_users_max=1):
             )
             nb_users = random.randrange(1, nb_users_max + 1)
             group.members = list({random.choice(users) for _ in range(nb_users)})
-            group.save()
+            BaseBackend.instance.save(group)
             groups.append(group)
         except Exception:  # pragma: no cover
             pass
diff --git a/canaille/oidc/endpoints/clients.py b/canaille/oidc/endpoints/clients.py
index 2cc541af..3f223a52 100644
--- a/canaille/oidc/endpoints/clients.py
+++ b/canaille/oidc/endpoints/clients.py
@@ -14,6 +14,7 @@ from canaille.app.flask import render_htmx_template
 from canaille.app.forms import TableForm
 from canaille.app.i18n import gettext as _
 from canaille.app.themes import render_template
+from canaille.backends import BaseBackend
 
 from .forms import ClientAddForm
 
@@ -73,9 +74,9 @@ def add(user):
         if form["token_endpoint_auth_method"].data == "none"
         else gen_salt(48),
     )
-    client.save()
+    BaseBackend.instance.save(client)
     client.audience = [client]
-    client.save()
+    BaseBackend.instance.save(client)
     flash(
         _("The client has been created."),
         "success",
@@ -137,7 +138,7 @@ def client_edit(client):
         audience=form["audience"].data,
         preconsent=form["preconsent"].data,
     )
-    client.save()
+    BaseBackend.instance.save(client)
     flash(
         _("The client has been edited."),
         "success",
diff --git a/canaille/oidc/endpoints/consents.py b/canaille/oidc/endpoints/consents.py
index 1dcff0be..bb2f9eb9 100644
--- a/canaille/oidc/endpoints/consents.py
+++ b/canaille/oidc/endpoints/consents.py
@@ -95,7 +95,7 @@ def restore(user, consent):
         consent.restore()
         if not consent.issue_date:
             consent.issue_date = datetime.datetime.now(datetime.timezone.utc)
-        consent.save()
+        BaseBackend.instance.save(consent)
         flash(_("The access has been restored"), "success")
 
     return redirect(url_for("oidc.consents.consents"))
@@ -119,7 +119,7 @@ def revoke_preconsent(user, client):
         scope=client.scope,
     )
     consent.revoke()
-    consent.save()
+    BaseBackend.instance.save(consent)
     flash(_("The access has been revoked"), "success")
 
     return redirect(url_for("oidc.consents.consents"))
diff --git a/canaille/oidc/endpoints/oauth.py b/canaille/oidc/endpoints/oauth.py
index 9810993c..c116ac81 100644
--- a/canaille/oidc/endpoints/oauth.py
+++ b/canaille/oidc/endpoints/oauth.py
@@ -177,7 +177,7 @@ def authorize_consent(client, user):
                 scope=allowed_scopes,
                 issue_date=datetime.datetime.now(datetime.timezone.utc),
             )
-        consent.save()
+        BaseBackend.instance.save(consent)
 
     response = authorization.create_authorization_response(grant_user=grant_user)
     current_app.logger.debug("authorization endpoint response: %s", response.location)
diff --git a/canaille/oidc/endpoints/tokens.py b/canaille/oidc/endpoints/tokens.py
index 234a255d..80587fcd 100644
--- a/canaille/oidc/endpoints/tokens.py
+++ b/canaille/oidc/endpoints/tokens.py
@@ -11,6 +11,7 @@ from canaille.app.flask import render_htmx_template
 from canaille.app.forms import TableForm
 from canaille.app.i18n import gettext as _
 from canaille.app.themes import render_template
+from canaille.backends import BaseBackend
 
 from .forms import TokenRevokationForm
 
@@ -40,7 +41,7 @@ def view(user, token):
 
         elif request.form.get("action") == "revoke":
             token.revokation_date = datetime.datetime.now(datetime.timezone.utc)
-            token.save()
+            BaseBackend.instance.save(token)
             flash(_("The token has successfully been revoked."), "success")
 
         else:
diff --git a/canaille/oidc/models.py b/canaille/oidc/models.py
index b4edbd8f..7e4da07b 100644
--- a/canaille/oidc/models.py
+++ b/canaille/oidc/models.py
@@ -184,7 +184,7 @@ class Consent(BaseConsent):
 
     def revoke(self):
         self.revokation_date = datetime.datetime.now(datetime.timezone.utc)
-        self.save()
+        BaseBackend.instance.save(self)
 
         tokens = BaseBackend.instance.query(
             models.Token,
@@ -194,8 +194,8 @@ class Consent(BaseConsent):
         tokens = [token for token in tokens if not token.revoked]
         for t in tokens:
             t.revokation_date = self.revokation_date
-            t.save()
+            BaseBackend.instance.save(t)
 
     def restore(self):
         self.revokation_date = None
-        self.save()
+        BaseBackend.instance.save(self)
diff --git a/canaille/oidc/oauth.py b/canaille/oidc/oauth.py
index a07efb6e..848140ec 100644
--- a/canaille/oidc/oauth.py
+++ b/canaille/oidc/oauth.py
@@ -228,7 +228,7 @@ def save_authorization_code(code, request):
         challenge=request.data.get("code_challenge"),
         challenge_method=request.data.get("code_challenge_method"),
     )
-    code.save()
+    BaseBackend.instance.save(code)
     return code.code
 
 
@@ -297,7 +297,7 @@ class RefreshTokenGrant(_RefreshTokenGrant):
 
     def revoke_old_credential(self, credential):
         credential.revokation_date = datetime.datetime.now(datetime.timezone.utc)
-        credential.save()
+        BaseBackend.instance.save(credential)
 
 
 class OpenIDImplicitGrant(_OpenIDImplicitGrant):
@@ -351,7 +351,7 @@ def save_token(token, request):
         subject=request.user,
         audience=request.client.audience,
     )
-    t.save()
+    BaseBackend.instance.save(t)
 
 
 class BearerTokenValidator(_BearerTokenValidator):
@@ -382,7 +382,7 @@ class RevocationEndpoint(_RevocationEndpoint):
 
     def revoke_token(self, token, request):
         token.revokation_date = datetime.datetime.now(datetime.timezone.utc)
-        token.save()
+        BaseBackend.instance.save(token)
 
 
 class IntrospectionEndpoint(_IntrospectionEndpoint):
@@ -463,9 +463,9 @@ class ClientRegistrationEndpoint(ClientManagementMixin, _ClientRegistrationEndpo
             post_logout_redirect_uris=request.data.get("post_logout_redirect_uris"),
             **self.client_convert_data(**client_info, **client_metadata),
         )
-        client.save()
+        BaseBackend.instance.save(client)
         client.audience = [client]
-        client.save()
+        BaseBackend.instance.save(client)
         return client
 
 
@@ -485,7 +485,7 @@ class ClientConfigurationEndpoint(ClientManagementMixin, _ClientConfigurationEnd
 
     def update_client(self, client, client_metadata, request):
         client.update(**self.client_convert_data(**client_metadata))
-        client.save()
+        BaseBackend.instance.save(client)
         return client
 
     def generate_client_registration_info(self, client, request):
diff --git a/tests/app/test_forms.py b/tests/app/test_forms.py
index e4afd25f..c9b8f97a 100644
--- a/tests/app/test_forms.py
+++ b/tests/app/test_forms.py
@@ -206,13 +206,13 @@ def test_fieldlist_add_readonly(testclient, logged_user):
     testclient.post("/profile/user", data, status=403)
 
 
-def test_fieldlist_remove_readonly(testclient, logged_user):
+def test_fieldlist_remove_readonly(testclient, logged_user, backend):
     testclient.app.config["CANAILLE"]["ACL"]["DEFAULT"]["WRITE"].remove("phone_numbers")
     testclient.app.config["CANAILLE"]["ACL"]["DEFAULT"]["READ"].append("phone_numbers")
     logged_user.reload()
 
     logged_user.phone_numbers = ["555-555-000", "555-555-111"]
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user")
     form = res.forms["baseform"]
diff --git a/tests/app/test_i18n.py b/tests/app/test_i18n.py
index 7185d705..ac9612c2 100644
--- a/tests/app/test_i18n.py
+++ b/tests/app/test_i18n.py
@@ -1,9 +1,9 @@
 from flask_babel import refresh
 
 
-def test_preferred_language(testclient, logged_user):
+def test_preferred_language(testclient, logged_user, backend):
     logged_user.preferred_language = None
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user", status=200)
     form = res.forms["baseform"]
@@ -49,9 +49,9 @@ def test_preferred_language(testclient, logged_user):
     res.mustcontain(no="Mon profil")
 
 
-def test_form_translations(testclient, logged_user):
+def test_form_translations(testclient, logged_user, backend):
     logged_user.preferred_language = "fr"
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user", status=200)
     form = res.forms["baseform"]
@@ -62,9 +62,9 @@ def test_form_translations(testclient, logged_user):
     res.mustcontain("N’est pas un numéro de téléphone valide")
 
 
-def test_language_config(testclient, logged_user):
+def test_language_config(testclient, logged_user, backend):
     logged_user.preferred_language = None
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user", status=200)
     assert res.pyquery("html")[0].attrib["lang"] == "en"
diff --git a/tests/backends/ldap/test_models.py b/tests/backends/ldap/test_models.py
index baea5416..8ee5cb91 100644
--- a/tests/backends/ldap/test_models.py
+++ b/tests/backends/ldap/test_models.py
@@ -7,7 +7,7 @@ def test_model_references_set_unsaved_object(
     """LDAP groups can be inconsistent by containing members which doesn't
     exist."""
     group = models.Group(members=[user], display_name="foo")
-    group.save()
+    backend.save(group)
     user.reload()
 
     non_existent_user = models.User(
@@ -16,7 +16,7 @@ def test_model_references_set_unsaved_object(
     group.members = group.members + [non_existent_user]
     assert group.members == [user, non_existent_user]
 
-    group.save()
+    backend.save(group)
     assert group.members == [user, non_existent_user]
 
     group.reload()
diff --git a/tests/backends/ldap/test_object_class.py b/tests/backends/ldap/test_object_class.py
index b7863459..8152cc2e 100644
--- a/tests/backends/ldap/test_object_class.py
+++ b/tests/backends/ldap/test_object_class.py
@@ -5,7 +5,7 @@ from canaille.backends.ldap.ldapobject import LDAPObject
 
 def test_guess_object_from_dn(backend, testclient, foo_group):
     foo_group.members = [foo_group]
-    foo_group.save()
+    backend.save(foo_group)
     dn = foo_group.dn
     g = backend.get(LDAPObject, dn)
     assert isinstance(g, models.Group)
@@ -18,7 +18,7 @@ def test_object_class_update(backend, testclient):
     setup_ldap_models(testclient.app.config)
 
     user1 = models.User(cn="foo1", sn="bar1", user_name="baz1")
-    user1.save()
+    backend.save(user1)
 
     assert set(user1.get_ldap_attribute("objectClass")) == {"inetOrgPerson"}
     assert set(
@@ -32,7 +32,7 @@ def test_object_class_update(backend, testclient):
     setup_ldap_models(testclient.app.config)
 
     user2 = models.User(cn="foo2", sn="bar2", user_name="baz2")
-    user2.save()
+    backend.save(user2)
 
     assert set(user2.get_ldap_attribute("objectClass")) == {
         "inetOrgPerson",
@@ -48,7 +48,7 @@ def test_object_class_update(backend, testclient):
     user1 = backend.get(models.User, id=user1.id)
     assert user1.get_ldap_attribute("objectClass") == ["inetOrgPerson"]
 
-    user1.save()
+    backend.save(user1)
     assert set(user1.get_ldap_attribute("objectClass")) == {
         "inetOrgPerson",
         "extensibleObject",
@@ -72,7 +72,7 @@ def test_keep_old_object_classes(backend, testclient, slapd_server):
     attributes.
     """
     user = models.User(cn="foo", sn="bar", user_name="baz")
-    user.save()
+    backend.save(user)
 
     ldif = f"""dn: {user.dn}
 changetype: modify
@@ -95,6 +95,6 @@ homeDirectory: /home/foobar
     user.reload()
 
     # saving an object should not raise a ldap.OBJECT_CLASS_VIOLATION exception
-    user.save()
+    backend.save(user)
 
     user.delete()
diff --git a/tests/backends/ldap/test_utils.py b/tests/backends/ldap/test_utils.py
index 36b87084..f14bfc0a 100644
--- a/tests/backends/ldap/test_utils.py
+++ b/tests/backends/ldap/test_utils.py
@@ -24,7 +24,7 @@ def test_object_creation(app, backend):
         emails=["john@doe.com"],
     )
     assert not user.exists
-    user.save()
+    backend.save(user)
     assert user.exists
 
     user = backend.get(models.User, id=user.id)
@@ -45,7 +45,7 @@ def test_dn_when_leading_space_in_id_attribute(testclient, backend):
         user_name=" user",
         emails=["john@doe.com"],
     )
-    user.save()
+    backend.save(user)
 
     dn = user.dn
     assert dn == "uid=user,ou=users,dc=mydomain,dc=tld"
@@ -66,7 +66,7 @@ def test_special_chars_in_rdn(testclient, backend):
         user_name="#user",  # special char
         emails=["john@doe.com"],
     )
-    user.save()
+    backend.save(user)
 
     dn = user.dn
     assert ldap.dn.is_dn(dn)
diff --git a/tests/backends/test_models.py b/tests/backends/test_models.py
index 57086a9f..9fe606e8 100644
--- a/tests/backends/test_models.py
+++ b/tests/backends/test_models.py
@@ -12,13 +12,13 @@ def test_model_comparison(testclient, backend):
         family_name="foo",
         formatted_name="foo",
     )
-    foo1.save()
+    backend.save(foo1)
     bar = models.User(
         user_name="bar",
         family_name="bar",
         formatted_name="bar",
     )
-    bar.save()
+    backend.save(bar)
     foo2 = backend.get(models.User, id=foo1.id)
 
     assert foo1 == foo2
@@ -41,7 +41,7 @@ def test_model_lifecycle(testclient, backend):
     assert not backend.query(models.User, id="invalid")
     assert not backend.get(models.User, id=user.id)
 
-    user.save()
+    backend.save(user)
 
     assert backend.query(models.User) == [user]
     assert backend.query(models.User, id=user.id) == [user]
@@ -72,7 +72,7 @@ def test_model_attribute_edition(testclient, backend):
         display_name="display_name",
         emails=["email1@user.com", "email2@user.com"],
     )
-    user.save()
+    backend.save(user)
 
     assert user.user_name == "user_name"
     assert user.family_name == "family_name"
@@ -85,7 +85,7 @@ def test_model_attribute_edition(testclient, backend):
 
     user.family_name = "new_family_name"
     user.emails = ["email1@user.com"]
-    user.save()
+    backend.save(user)
 
     assert user.family_name == "new_family_name"
     assert user.emails == ["email1@user.com"]
@@ -97,7 +97,7 @@ def test_model_attribute_edition(testclient, backend):
     user.display_name = ""
     assert not user.display_name
 
-    user.save()
+    backend.save(user)
     assert not user.display_name
 
     user.delete()
@@ -110,7 +110,7 @@ def test_model_indexation(testclient, backend):
         formatted_name="formatted_name",
         emails=["email1@user.com", "email2@user.com"],
     )
-    user.save()
+    backend.save(user)
 
     assert backend.get(models.User, family_name="family_name") == user
     assert not backend.get(models.User, family_name="new_family_name")
@@ -125,7 +125,7 @@ def test_model_indexation(testclient, backend):
     assert backend.get(models.User, emails=["email1@user.com"]) != user
     assert not backend.get(models.User, emails=["email3@user.com"])
 
-    user.save()
+    backend.save(user)
 
     assert not backend.get(models.User, family_name="family_name")
     assert backend.get(models.User, family_name="new_family_name") == user
@@ -177,14 +177,14 @@ def test_model_references(testclient, user, foo_group, admin, bar_group, backend
     assert user not in bar_group.members
     assert bar_group not in user.groups
     user.groups = user.groups + [bar_group]
-    user.save()
+    backend.save(user)
     bar_group.reload()
 
     assert user in bar_group.members
     assert bar_group in user.groups
 
     bar_group.members = [admin]
-    bar_group.save()
+    backend.save(bar_group)
     user.reload()
 
     assert user not in bar_group.members
@@ -201,7 +201,7 @@ def test_model_creation_edition_datetime(testclient, backend):
             family_name="foo",
             formatted_name="foo",
         )
-        user.save()
+        backend.save(user)
         assert user.created == datetime.datetime(
             2020, 1, 1, 2, tzinfo=datetime.timezone.utc
         )
@@ -211,7 +211,7 @@ def test_model_creation_edition_datetime(testclient, backend):
 
     with time_machine.travel("2021-01-01 02:00:00+00:00", tick=False):
         user.family_name = "bar"
-        user.save()
+        backend.save(user)
         assert user.created == datetime.datetime(
             2020, 1, 1, 2, tzinfo=datetime.timezone.utc
         )
diff --git a/tests/conftest.py b/tests/conftest.py
index 8143126f..fa0a5319 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -191,7 +191,7 @@ def user(app, backend):
         profile_url="https://john.example",
         formatted_address="1235, somewhere",
     )
-    u.save()
+    backend.save(u)
     yield u
     u.delete()
 
@@ -205,7 +205,7 @@ def admin(app, backend):
         emails=["jane@doe.com"],
         password="admin",
     )
-    u.save()
+    backend.save(u)
     yield u
     u.delete()
 
@@ -219,7 +219,7 @@ def moderator(app, backend):
         emails=["jack@doe.com"],
         password="moderator",
     )
-    u.save()
+    backend.save(u)
     yield u
     u.delete()
 
@@ -251,7 +251,7 @@ def foo_group(app, user, backend):
         members=[user],
         display_name="foo",
     )
-    group.save()
+    backend.save(group)
     user.reload()
     yield group
     group.delete()
@@ -263,7 +263,7 @@ def bar_group(app, admin, backend):
         members=[admin],
         display_name="bar",
     )
-    group.save()
+    backend.save(group)
     admin.reload()
     yield group
     group.delete()
diff --git a/tests/core/test_account.py b/tests/core/test_account.py
index 133d2374..a7fb293a 100644
--- a/tests/core/test_account.py
+++ b/tests/core/test_account.py
@@ -27,7 +27,7 @@ def test_user_deleted_in_session(testclient, backend):
         emails=["jake@doe.com"],
         password="correct horse battery staple",
     )
-    u.save()
+    backend.save(u)
     testclient.get("/profile/jake", status=403)
 
     with testclient.session_transaction() as session:
@@ -66,7 +66,7 @@ def test_admin_self_deletion(testclient, backend):
         emails=["temp@temp.com"],
         password="admin",
     )
-    admin.save()
+    backend.save(admin)
     with testclient.session_transaction() as sess:
         sess["user_id"] = [admin.id]
 
@@ -92,7 +92,7 @@ def test_user_self_deletion(testclient, backend):
         emails=["temp@temp.com"],
         password="correct horse battery staple",
     )
-    user.save()
+    backend.save(user)
     with testclient.session_transaction() as sess:
         sess["user_id"] = [user.id]
 
@@ -134,7 +134,7 @@ def test_account_locking(user, backend):
 
     user.lock_date = datetime.datetime.now(datetime.timezone.utc)
     assert user.locked
-    user.save()
+    backend.save(user)
     assert user.locked
     assert backend.get(models.User, id=user.id).locked
     assert backend.check_user_password(user, "correct horse battery staple") == (
@@ -143,7 +143,7 @@ def test_account_locking(user, backend):
     )
 
     user.lock_date = None
-    user.save()
+    backend.save(user)
     assert not user.locked
     assert not backend.get(models.User, id=user.id).locked
     assert backend.check_user_password(user, "correct horse battery staple") == (
@@ -163,7 +163,7 @@ def test_account_locking_past_date(user, backend):
     user.lock_date = datetime.datetime.now(datetime.timezone.utc).replace(
         microsecond=0
     ) - datetime.timedelta(days=30)
-    user.save()
+    backend.save(user)
     assert user.locked
     assert backend.get(models.User, id=user.id).locked
     assert backend.check_user_password(user, "correct horse battery staple") == (
@@ -183,7 +183,7 @@ def test_account_locking_future_date(user, backend):
     user.lock_date = datetime.datetime.now(datetime.timezone.utc).replace(
         microsecond=0
     ) + datetime.timedelta(days=365 * 4)
-    user.save()
+    backend.save(user)
     assert not user.locked
     assert not backend.get(models.User, id=user.id).locked
     assert backend.check_user_password(user, "correct horse battery staple") == (
@@ -192,7 +192,7 @@ def test_account_locking_future_date(user, backend):
     )
 
 
-def test_account_locked_during_session(testclient, logged_user):
+def test_account_locked_during_session(testclient, logged_user, backend):
     logged_user.lock_date = datetime.datetime.now(datetime.timezone.utc)
-    logged_user.save()
+    backend.save(logged_user)
     testclient.get("/profile/user/settings", status=403)
diff --git a/tests/core/test_auth.py b/tests/core/test_auth.py
index 2b873616..b6e5718e 100644
--- a/tests/core/test_auth.py
+++ b/tests/core/test_auth.py
@@ -154,7 +154,7 @@ def test_user_without_password_first_login(testclient, backend, smtpd):
         user_name="temp",
         emails=["john@doe.com", "johhny@doe.com"],
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/login", status=200)
     res.form["login"] = "temp"
@@ -189,7 +189,7 @@ def test_first_login_account_initialization_mail_sending_failed(
         user_name="temp",
         emails=["john@doe.com"],
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/firstlogin/temp")
     res = res.form.submit(name="action", value="sendmail", expect_errors=True)
@@ -211,7 +211,7 @@ def test_first_login_form_error(testclient, backend, smtpd):
         user_name="temp",
         emails=["john@doe.com"],
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/firstlogin/temp", status=200)
     res.form["csrf_token"] = "invalid"
@@ -236,7 +236,7 @@ def test_user_password_deleted_during_login(testclient, backend):
         emails=["john@doe.com"],
         password="correct horse battery staple",
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/login")
     res.form["login"] = "temp"
@@ -244,7 +244,7 @@ def test_user_password_deleted_during_login(testclient, backend):
     res.form["password"] = "correct horse battery staple"
 
     u.password = None
-    u.save()
+    backend.save(u)
 
     res = res.form.submit(status=302)
     assert res.location == "/firstlogin/temp"
@@ -272,12 +272,12 @@ def test_wrong_login(testclient, user):
     res.mustcontain("The login 'invalid' does not exist")
 
 
-def test_signin_locked_account(testclient, user):
+def test_signin_locked_account(testclient, user, backend):
     with testclient.session_transaction() as session:
         assert not session.get("user_id")
 
     user.lock_date = datetime.datetime.now(datetime.timezone.utc)
-    user.save()
+    backend.save(user)
 
     res = testclient.get("/login", status=200)
     res.form["login"] = "user"
@@ -289,4 +289,4 @@ def test_signin_locked_account(testclient, user):
     res.mustcontain("Your account has been locked.")
 
     user.lock_date = None
-    user.save()
+    backend.save(user)
diff --git a/tests/core/test_email_confirmation.py b/tests/core/test_email_confirmation.py
index c8ff1730..cf676234 100644
--- a/tests/core/test_email_confirmation.py
+++ b/tests/core/test_email_confirmation.py
@@ -371,14 +371,14 @@ def test_confirmation_email_already_used_link(testclient, backend, user, admin):
     assert "new_email@mydomain.tld" not in user.emails
 
 
-def test_delete_email(testclient, logged_user):
+def test_delete_email(testclient, logged_user, backend):
     """Tests that user can deletes its emails unless they have only one
     left."""
     res = testclient.get("/profile/user")
     assert "email_remove" not in res.forms["emailconfirmationform"].fields
 
     logged_user.emails = logged_user.emails + ["new@email.com"]
-    logged_user.save()
+    backend.save(logged_user)
     res = testclient.get("/profile/user")
     assert "email_remove" in res.forms["emailconfirmationform"].fields
 
@@ -391,10 +391,10 @@ def test_delete_email(testclient, logged_user):
     assert logged_user.emails == ["john@doe.com"]
 
 
-def test_delete_wrong_email(testclient, logged_user):
+def test_delete_wrong_email(testclient, logged_user, backend):
     """Tests that removing an already removed email do not produce anything."""
     logged_user.emails = logged_user.emails + ["new@email.com"]
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user")
 
@@ -412,10 +412,10 @@ def test_delete_wrong_email(testclient, logged_user):
     assert logged_user.emails == ["john@doe.com"]
 
 
-def test_delete_last_email(testclient, logged_user):
+def test_delete_last_email(testclient, logged_user, backend):
     """Tests that users cannot remove their last email address."""
     logged_user.emails = logged_user.emails + ["new@email.com"]
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.get("/profile/user")
 
diff --git a/tests/core/test_forgotten_password.py b/tests/core/test_forgotten_password.py
index 5c2342d1..ee4568d5 100644
--- a/tests/core/test_forgotten_password.py
+++ b/tests/core/test_forgotten_password.py
@@ -26,9 +26,9 @@ def test_password_forgotten(smtpd, testclient, user):
     assert len(smtpd.messages) == 1
 
 
-def test_password_forgotten_multiple_mails(smtpd, testclient, user):
+def test_password_forgotten_multiple_mails(smtpd, testclient, user, backend):
     user.emails = ["foo@bar.com", "foo@baz.com", "foo@foo.com"]
-    user.save()
+    backend.save(user)
 
     res = testclient.get("/reset", status=200)
 
diff --git a/tests/core/test_groups.py b/tests/core/test_groups.py
index bd9d6bb3..01605086 100644
--- a/tests/core/test_groups.py
+++ b/tests/core/test_groups.py
@@ -53,13 +53,13 @@ def test_group_deletion(testclient, backend):
         user_name="foobar",
         emails=["foo@bar.com"],
     )
-    user.save()
+    backend.save(user)
 
     group = models.Group(
         members=[user],
         display_name="foobar",
     )
-    group.save()
+    backend.save(group)
 
     user.reload()
     assert user.groups == [group]
@@ -86,19 +86,19 @@ def test_group_list_search(testclient, logged_admin, foo_group, bar_group):
     res.mustcontain(no=bar_group.display_name)
 
 
-def test_set_groups(app, user, foo_group, bar_group):
+def test_set_groups(app, user, foo_group, bar_group, backend):
     assert user in foo_group.members
     assert user.groups == [foo_group]
 
     user.groups = [foo_group, bar_group]
-    user.save()
+    backend.save(user)
 
     bar_group.reload()
     assert user in bar_group.members
     assert bar_group in user.groups
 
     user.groups = [foo_group]
-    user.save()
+    backend.save(user)
 
     foo_group.reload()
     bar_group.reload()
@@ -106,23 +106,23 @@ def test_set_groups(app, user, foo_group, bar_group):
     assert user not in bar_group.members
 
 
-def test_set_groups_with_leading_space_in_user_id_attribute(app, foo_group):
+def test_set_groups_with_leading_space_in_user_id_attribute(app, foo_group, backend):
     user = models.User(
         formatted_name=" Doe",  # leading space in id attribute
         family_name="Doe",
         user_name="user2",
         emails=["john@doe.com"],
     )
-    user.save()
+    backend.save(user)
 
     user.groups = [foo_group]
-    user.save()
+    backend.save(user)
 
     foo_group.reload()
     assert user in foo_group.members
 
     user.groups = []
-    user.save()
+    backend.save(user)
 
     foo_group.reload()
     assert user.id not in foo_group.members
@@ -231,14 +231,14 @@ def test_edition_failed(testclient, logged_moderator, foo_group):
     assert foo_group.display_name == "foo"
 
 
-def test_user_list_pagination(testclient, logged_admin, foo_group):
+def test_user_list_pagination(testclient, logged_admin, foo_group, backend):
     res = testclient.get("/groups/foo")
     res.mustcontain("1 item")
 
     users = fake_users(25)
     for user in users:
         foo_group.members = foo_group.members + [user]
-    foo_group.save()
+    backend.save(foo_group)
 
     assert len(foo_group.members) == 26
     res = testclient.get("/groups/foo")
@@ -274,9 +274,11 @@ def test_user_list_bad_pages(testclient, logged_admin, foo_group):
     )
 
 
-def test_user_list_search(testclient, logged_admin, foo_group, user, moderator):
+def test_user_list_search(
+    testclient, logged_admin, foo_group, user, moderator, backend
+):
     foo_group.members = foo_group.members + [logged_admin, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     res.mustcontain("3 items")
@@ -294,9 +296,9 @@ def test_user_list_search(testclient, logged_admin, foo_group, user, moderator):
     res.mustcontain(no=moderator.formatted_name)
 
 
-def test_remove_member(testclient, logged_admin, foo_group, user, moderator):
+def test_remove_member(testclient, logged_admin, foo_group, user, moderator, backend):
     foo_group.members = [user, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     form = res.forms[f"deletegroupmemberform-{user.id}"]
@@ -313,15 +315,15 @@ def test_remove_member(testclient, logged_admin, foo_group, user, moderator):
 
 
 def test_remove_member_already_remove_from_group(
-    testclient, logged_admin, foo_group, user, moderator
+    testclient, logged_admin, foo_group, user, moderator, backend
 ):
     foo_group.members = [user, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     form = res.forms[f"deletegroupmemberform-{user.id}"]
     foo_group.members = [moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = form.submit(name="action", value="confirm-remove-member")
     assert (
@@ -331,17 +333,17 @@ def test_remove_member_already_remove_from_group(
 
 
 def test_confirm_remove_member_already_removed_from_group(
-    testclient, logged_admin, foo_group, user, moderator
+    testclient, logged_admin, foo_group, user, moderator, backend
 ):
     foo_group.members = [user, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     form = res.forms[f"deletegroupmemberform-{user.id}"]
     res = form.submit(name="action", value="confirm-remove-member")
 
     foo_group.members = [moderator]
-    foo_group.save()
+    backend.save(foo_group)
     res = res.form.submit(name="action", value="remove-member")
 
     assert (
@@ -351,10 +353,10 @@ def test_confirm_remove_member_already_removed_from_group(
 
 
 def test_remove_member_already_deleted(
-    testclient, logged_admin, foo_group, user, moderator
+    testclient, logged_admin, foo_group, user, moderator, backend
 ):
     foo_group.members = [user, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     form = res.forms[f"deletegroupmemberform-{user.id}"]
@@ -368,10 +370,10 @@ def test_remove_member_already_deleted(
 
 
 def test_confirm_remove_member_already_deleted(
-    testclient, logged_admin, foo_group, user, moderator
+    testclient, logged_admin, foo_group, user, moderator, backend
 ):
     foo_group.members = [user, moderator]
-    foo_group.save()
+    backend.save(foo_group)
 
     res = testclient.get("/groups/foo")
     form = res.forms[f"deletegroupmemberform-{user.id}"]
diff --git a/tests/core/test_models.py b/tests/core/test_models.py
index 9d352164..8fc66247 100644
--- a/tests/core/test_models.py
+++ b/tests/core/test_models.py
@@ -13,13 +13,13 @@ def test_user_has_password(testclient, backend):
         user_name="temp",
         emails=["john@doe.com"],
     )
-    user.save()
+    backend.save(user)
 
     assert user.password is None
     assert not user.has_password()
 
     user.password = "foobar"
-    user.save()
+    backend.save(user)
 
     assert user.password is not None
     assert user.has_password()
diff --git a/tests/core/test_password_reset.py b/tests/core/test_password_reset.py
index 3249a31d..dc7fec8f 100644
--- a/tests/core/test_password_reset.py
+++ b/tests/core/test_password_reset.py
@@ -25,7 +25,7 @@ def test_password_reset(testclient, user, backend):
 
 def test_password_reset_multiple_emails(testclient, user, backend):
     user.emails = ["foo@bar.com", "foo@baz.com"]
-    user.save()
+    backend.save(user)
 
     assert not backend.check_user_password(user, "foobarbaz")[0]
     hash = build_hash("user", "foo@baz.com", user.password)
diff --git a/tests/core/test_profile_edition.py b/tests/core/test_profile_edition.py
index e22fc50b..6f8cfc96 100644
--- a/tests/core/test_profile_edition.py
+++ b/tests/core/test_profile_edition.py
@@ -118,6 +118,7 @@ def test_edition(
     logged_user,
     admin,
     jpeg_photo,
+    backend,
 ):
     res = testclient.get("/profile/user", status=200)
     form = res.forms["baseform"]
@@ -168,13 +169,14 @@ def test_edition(
     logged_user.emails = ["john@doe.com"]
     logged_user.given_name = None
     logged_user.photo = None
-    logged_user.save()
+    backend.save(logged_user)
 
 
 def test_edition_remove_fields(
     testclient,
     logged_user,
     admin,
+    backend,
 ):
     res = testclient.get("/profile/user", status=200)
     form = res.forms["baseform"]
@@ -195,13 +197,13 @@ def test_edition_remove_fields(
     logged_user.emails = ["john@doe.com"]
     logged_user.given_name = None
     logged_user.photo = None
-    logged_user.save()
+    backend.save(logged_user)
 
 
-def test_field_permissions_none(testclient, logged_user):
+def test_field_permissions_none(testclient, logged_user, backend):
     testclient.get("/profile/user", status=200)
     logged_user.phone_numbers = ["555-666-777"]
-    logged_user.save()
+    backend.save(logged_user)
 
     testclient.app.config["CANAILLE"]["ACL"]["DEFAULT"] = {
         "READ": ["user_name"],
@@ -227,10 +229,10 @@ def test_field_permissions_none(testclient, logged_user):
     assert logged_user.phone_numbers == ["555-666-777"]
 
 
-def test_field_permissions_read(testclient, logged_user):
+def test_field_permissions_read(testclient, logged_user, backend):
     testclient.get("/profile/user", status=200)
     logged_user.phone_numbers = ["555-666-777"]
-    logged_user.save()
+    backend.save(logged_user)
 
     testclient.app.config["CANAILLE"]["ACL"]["DEFAULT"] = {
         "READ": ["user_name", "phone_numbers"],
@@ -255,10 +257,10 @@ def test_field_permissions_read(testclient, logged_user):
     assert logged_user.phone_numbers == ["555-666-777"]
 
 
-def test_field_permissions_write(testclient, logged_user):
+def test_field_permissions_write(testclient, logged_user, backend):
     testclient.get("/profile/user", status=200)
     logged_user.phone_numbers = ["555-666-777"]
-    logged_user.save()
+    backend.save(logged_user)
 
     testclient.app.config["CANAILLE"]["ACL"]["DEFAULT"] = {
         "READ": ["user_name"],
diff --git a/tests/core/test_profile_photo.py b/tests/core/test_profile_photo.py
index d173565a..466c4bf6 100644
--- a/tests/core/test_profile_photo.py
+++ b/tests/core/test_profile_photo.py
@@ -5,9 +5,9 @@ from webtest import Upload
 from canaille.app import models
 
 
-def test_photo(testclient, user, jpeg_photo):
+def test_photo(testclient, user, jpeg_photo, backend):
     user.photo = jpeg_photo
-    user.save()
+    backend.save(user)
     user.reload()
 
     res = testclient.get("/profile/user/photo")
diff --git a/tests/core/test_profile_settings.py b/tests/core/test_profile_settings.py
index 6c159c34..547e77cf 100644
--- a/tests/core/test_profile_settings.py
+++ b/tests/core/test_profile_settings.py
@@ -34,13 +34,13 @@ def test_edition(testclient, logged_user, admin, foo_group, bar_group, backend):
     assert backend.check_user_password(logged_user, "correct horse battery staple")[0]
 
     logged_user.user_name = "user"
-    logged_user.save()
+    backend.save(logged_user)
 
 
 def test_group_removal(testclient, logged_admin, user, foo_group, backend):
     """Tests that one can remove a group from a user."""
     foo_group.members = [user, logged_admin]
-    foo_group.save()
+    backend.save(foo_group)
     user.reload()
     assert foo_group in user.groups
 
@@ -115,7 +115,7 @@ def test_edition_without_groups(
     assert backend.check_user_password(logged_user, "correct horse battery staple")[0]
 
     logged_user.user_name = "user"
-    logged_user.save()
+    backend.save(logged_user)
 
 
 def test_password_change(testclient, logged_user, backend):
@@ -171,7 +171,7 @@ def test_password_initialization_mail(smtpd, testclient, backend, logged_admin):
         user_name="temp",
         emails=["john@doe.com"],
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/profile/temp/settings", status=200)
     res.mustcontain("This user does not have a password yet")
@@ -188,7 +188,7 @@ def test_password_initialization_mail(smtpd, testclient, backend, logged_admin):
 
     u.reload()
     u.password = "correct horse battery staple"
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/profile/temp/settings", status=200)
     res.mustcontain(no="This user does not have a password yet")
@@ -207,7 +207,7 @@ def test_password_initialization_mail_send_fail(
         user_name="temp",
         emails=["john@doe.com"],
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/profile/temp/settings", status=200)
     res.mustcontain("This user does not have a password yet")
@@ -272,7 +272,7 @@ def test_impersonate_locked_user(testclient, backend, logged_admin, user):
     user.lock_date = datetime.datetime.now(datetime.timezone.utc) - datetime.timedelta(
         days=1
     )
-    user.save()
+    backend.save(user)
 
     assert user.locked
     res = testclient.get("/profile/user/settings")
@@ -295,7 +295,7 @@ def test_password_reset_email(smtpd, testclient, backend, logged_admin):
         emails=["john@doe.com"],
         password="correct horse battery staple",
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/profile/temp/settings", status=200)
     res.mustcontain("If the user has forgotten his password")
@@ -323,7 +323,7 @@ def test_password_reset_email_failed(SMTP, smtpd, testclient, backend, logged_ad
         emails=["john@doe.com"],
         password="correct horse battery staple",
     )
-    u.save()
+    backend.save(u)
 
     res = testclient.get("/profile/temp/settings", status=200)
     res.mustcontain("If the user has forgotten his password")
@@ -454,7 +454,7 @@ def test_empty_lock_date(
         second=0, microsecond=0
     ) + datetime.timedelta(days=30)
     user.lock_date = expiration_datetime
-    user.save()
+    backend.save(user)
 
     res = testclient.get("/profile/user/settings", status=200)
     res.form["lock_date"] = ""
diff --git a/tests/oidc/commands/test_clean.py b/tests/oidc/commands/test_clean.py
index 69daf252..dba69479 100644
--- a/tests/oidc/commands/test_clean.py
+++ b/tests/oidc/commands/test_clean.py
@@ -21,7 +21,7 @@ def test_clean_command(testclient, backend, client, user):
         challenge="challenge",
         challenge_method="method",
     )
-    valid_code.save()
+    backend.save(valid_code)
     expired_code = models.AuthorizationCode(
         authorization_code_id=gen_salt(48),
         code="my-expired-code",
@@ -39,7 +39,7 @@ def test_clean_command(testclient, backend, client, user):
         challenge="challenge",
         challenge_method="method",
     )
-    expired_code.save()
+    backend.save(expired_code)
 
     valid_token = models.Token(
         token_id=gen_salt(48),
@@ -53,7 +53,7 @@ def test_clean_command(testclient, backend, client, user):
         ),
         lifetime=3600,
     )
-    valid_token.save()
+    backend.save(valid_token)
     expired_token = models.Token(
         token_id=gen_salt(48),
         access_token="my-expired-token",
@@ -67,7 +67,7 @@ def test_clean_command(testclient, backend, client, user):
         ),
         lifetime=3600,
     )
-    expired_token.save()
+    backend.save(expired_token)
 
     assert backend.get(models.AuthorizationCode, code="my-expired-code")
     assert backend.get(models.Token, access_token="my-expired-token")
diff --git a/tests/oidc/conftest.py b/tests/oidc/conftest.py
index f4cc958d..c83baf6e 100644
--- a/tests/oidc/conftest.py
+++ b/tests/oidc/conftest.py
@@ -67,9 +67,9 @@ def client(testclient, trusted_client, backend):
         token_endpoint_auth_method="client_secret_basic",
         post_logout_redirect_uris=["https://mydomain.tld/disconnected"],
     )
-    c.save()
+    backend.save(c)
     c.audience = [c, trusted_client]
-    c.save()
+    backend.save(c)
 
     yield c
     c.delete()
@@ -105,9 +105,9 @@ def trusted_client(testclient, backend):
         post_logout_redirect_uris=["https://myotherdomain.tld/disconnected"],
         preconsent=True,
     )
-    c.save()
+    backend.save(c)
     c.audience = [c]
-    c.save()
+    backend.save(c)
 
     yield c
     c.delete()
@@ -129,7 +129,7 @@ def authorization(testclient, user, client, backend):
         challenge="challenge",
         challenge_method="method",
     )
-    a.save()
+    backend.save(a)
     yield a
     a.delete()
 
@@ -147,7 +147,7 @@ def token(testclient, client, user, backend):
         issue_date=datetime.datetime.now(datetime.timezone.utc),
         lifetime=3600,
     )
-    t.save()
+    backend.save(t)
     yield t
     t.delete()
 
@@ -171,6 +171,6 @@ def consent(testclient, client, user, backend):
         scope=["openid", "profile"],
         issue_date=datetime.datetime.now(datetime.timezone.utc),
     )
-    t.save()
+    backend.save(t)
     yield t
     t.delete()
diff --git a/tests/oidc/test_authorization_code_flow.py b/tests/oidc/test_authorization_code_flow.py
index 9c8d30e5..bdee6ec7 100644
--- a/tests/oidc/test_authorization_code_flow.py
+++ b/tests/oidc/test_authorization_code_flow.py
@@ -167,7 +167,7 @@ def test_preconsented_client(
     assert not backend.query(models.Consent)
 
     client.preconsent = True
-    client.save()
+    backend.save(client)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -318,7 +318,7 @@ def test_code_challenge(testclient, logged_user, client, backend):
     assert not backend.query(models.Consent)
 
     client.token_endpoint_auth_method = "none"
-    client.save()
+    backend.save(client)
 
     code_verifier = gen_salt(48)
     code_challenge = create_s256_code_challenge(code_verifier)
@@ -373,7 +373,7 @@ def test_code_challenge(testclient, logged_user, client, backend):
     assert res.json["name"] == "John (johnny) Doe"
 
     client.token_endpoint_auth_method = "client_secret_basic"
-    client.save()
+    backend.save(client)
 
     for consent in consents:
         consent.delete()
@@ -565,7 +565,7 @@ def test_nonce_not_required_in_oauth_requests(testclient, logged_user, client, b
 def test_request_scope_too_large(testclient, logged_user, keypair, client, backend):
     assert not backend.query(models.Consent)
     client.scope = ["openid", "profile", "groups"]
-    client.save()
+    backend.save(client)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -679,7 +679,7 @@ def test_code_with_invalid_user(testclient, admin, client, backend):
         emails=["temp@temp.com"],
         password="correct horse battery staple",
     )
-    user.save()
+    backend.save(user)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -738,7 +738,7 @@ def test_locked_account(
     )
 
     logged_user.lock_date = datetime.datetime.now(datetime.timezone.utc)
-    logged_user.save()
+    backend.save(logged_user)
 
     res = res.form.submit(name="answer", value="accept", status=302)
 
diff --git a/tests/oidc/test_authorization_prompt.py b/tests/oidc/test_authorization_prompt.py
index 4e20ecc9..05275eb9 100644
--- a/tests/oidc/test_authorization_prompt.py
+++ b/tests/oidc/test_authorization_prompt.py
@@ -14,7 +14,7 @@ from canaille.app import models
 from canaille.core.endpoints.account import RegistrationPayload
 
 
-def test_prompt_none(testclient, logged_user, client):
+def test_prompt_none(testclient, logged_user, client, backend):
     """Nominal case with prompt=none."""
     consent = models.Consent(
         consent_id=str(uuid.uuid4()),
@@ -22,7 +22,7 @@ def test_prompt_none(testclient, logged_user, client):
         subject=logged_user,
         scope=["openid", "profile"],
     )
-    consent.save()
+    backend.save(consent)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -42,7 +42,7 @@ def test_prompt_none(testclient, logged_user, client):
     consent.delete()
 
 
-def test_prompt_not_logged(testclient, user, client):
+def test_prompt_not_logged(testclient, user, client, backend):
     """Prompt=none should return a login_required error when no user is logged
     in.
 
@@ -58,7 +58,7 @@ def test_prompt_not_logged(testclient, user, client):
         subject=user,
         scope=["openid", "profile"],
     )
-    consent.save()
+    backend.save(consent)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -100,7 +100,7 @@ def test_prompt_no_consent(testclient, logged_user, client):
     assert "consent_required" == res.json.get("error")
 
 
-def test_prompt_create_logged(testclient, logged_user, client):
+def test_prompt_create_logged(testclient, logged_user, client, backend):
     """If prompt=create and user is already logged in, then go straight to the
     consent page."""
     testclient.app.config["CANAILLE"]["ENABLE_REGISTRATION"] = True
@@ -111,7 +111,7 @@ def test_prompt_create_logged(testclient, logged_user, client):
         subject=logged_user,
         scope=["openid", "profile"],
     )
-    consent.save()
+    backend.save(consent)
 
     res = testclient.get(
         "/oauth/authorize",
diff --git a/tests/oidc/test_client_admin.py b/tests/oidc/test_client_admin.py
index c42bf219..cbba9dc0 100644
--- a/tests/oidc/test_client_admin.py
+++ b/tests/oidc/test_client_admin.py
@@ -22,13 +22,15 @@ def test_client_list(testclient, client, logged_admin):
     res.mustcontain(client.client_name)
 
 
-def test_client_list_pagination(testclient, logged_admin, client, trusted_client):
+def test_client_list_pagination(
+    testclient, logged_admin, client, trusted_client, backend
+):
     res = testclient.get("/admin/client")
     res.mustcontain("2 items")
     clients = []
     for _ in range(25):
         client = models.Client(client_id=gen_salt(48), client_name=gen_salt(48))
-        client.save()
+        backend.save(client)
         clients.append(client)
 
     res = testclient.get("/admin/client")
@@ -216,22 +218,22 @@ def test_client_edit_missing_fields(testclient, client, logged_admin, trusted_cl
 
 def test_client_delete(testclient, logged_admin, backend):
     client = models.Client(client_id="client_id")
-    client.save()
+    backend.save(client)
     token = models.Token(
         token_id="id",
         client=client,
         subject=logged_admin,
         issue_date=datetime.datetime.now(datetime.timezone.utc),
     )
-    token.save()
+    backend.save(token)
     consent = models.Consent(
         consent_id="consent_id", subject=logged_admin, client=client, scope=["openid"]
     )
-    consent.save()
+    backend.save(consent)
     authorization_code = models.AuthorizationCode(
         authorization_code_id="id", client=client, subject=logged_admin
     )
-    authorization_code.save()
+    backend.save(authorization_code)
 
     res = testclient.get("/admin/client/edit/" + client.client_id)
     res = res.forms["clientaddform"].submit(name="action", value="confirm-delete")
diff --git a/tests/oidc/test_code_admin.py b/tests/oidc/test_code_admin.py
index d41cb870..9a79ecb4 100644
--- a/tests/oidc/test_code_admin.py
+++ b/tests/oidc/test_code_admin.py
@@ -16,7 +16,7 @@ def test_authorizaton_list(testclient, authorization, logged_admin):
     res.mustcontain(authorization.authorization_code_id)
 
 
-def test_authorization_list_pagination(testclient, logged_admin, client):
+def test_authorization_list_pagination(testclient, logged_admin, client, backend):
     res = testclient.get("/admin/authorization")
     res.mustcontain("0 items")
     authorizations = []
@@ -24,7 +24,7 @@ def test_authorization_list_pagination(testclient, logged_admin, client):
         code = models.AuthorizationCode(
             authorization_code_id=gen_salt(48), client=client, subject=logged_admin
         )
-        code.save()
+        backend.save(code)
         authorizations.append(code)
 
     res = testclient.get("/admin/authorization")
@@ -64,18 +64,18 @@ def test_authorization_list_bad_pages(testclient, logged_admin):
     )
 
 
-def test_authorization_list_search(testclient, logged_admin, client):
+def test_authorization_list_search(testclient, logged_admin, client, backend):
     id1 = gen_salt(48)
     auth1 = models.AuthorizationCode(
         authorization_code_id=id1, client=client, subject=logged_admin
     )
-    auth1.save()
+    backend.save(auth1)
 
     id2 = gen_salt(48)
     auth2 = models.AuthorizationCode(
         authorization_code_id=id2, client=client, subject=logged_admin
     )
-    auth2.save()
+    backend.save(auth2)
 
     res = testclient.get("/admin/authorization")
     res.mustcontain("2 items")
diff --git a/tests/oidc/test_consent.py b/tests/oidc/test_consent.py
index 16787021..8edc86ab 100644
--- a/tests/oidc/test_consent.py
+++ b/tests/oidc/test_consent.py
@@ -139,13 +139,15 @@ def test_oidc_authorization_after_revokation(
     assert token.subject == logged_user
 
 
-def test_preconsented_client_appears_in_consent_list(testclient, client, logged_user):
+def test_preconsented_client_appears_in_consent_list(
+    testclient, client, logged_user, backend
+):
     assert not client.preconsent
     res = testclient.get("/consent/pre-consents")
     res.mustcontain(no=client.client_name)
 
     client.preconsent = True
-    client.save()
+    backend.save(client)
 
     res = testclient.get("/consent/pre-consents")
     res.mustcontain(client.client_name)
@@ -153,7 +155,7 @@ def test_preconsented_client_appears_in_consent_list(testclient, client, logged_
 
 def test_revoke_preconsented_client(testclient, client, logged_user, token, backend):
     client.preconsent = True
-    client.save()
+    backend.save(client)
     assert not backend.get(models.Consent)
     assert not token.revoked
 
@@ -190,22 +192,22 @@ def test_revoke_invalid_preconsented_client(testclient, logged_user):
 
 
 def test_revoke_preconsented_client_with_manual_consent(
-    testclient, logged_user, client, consent
+    testclient, logged_user, client, consent, backend
 ):
     client.preconsent = True
-    client.save()
+    backend.save(client)
     res = testclient.get(f"/consent/revoke-preconsent/{client.client_id}", status=302)
     res = res.follow()
     assert ("success", "The access has been revoked") in res.flashes
 
 
 def test_revoke_preconsented_client_with_manual_revokation(
-    testclient, logged_user, client, consent
+    testclient, logged_user, client, consent, backend
 ):
     client.preconsent = True
-    client.save()
+    backend.save(client)
     consent.revoke()
-    consent.save()
+    backend.save(consent)
 
     res = testclient.get(f"/consent/revoke-preconsent/{client.client_id}", status=302)
     res = res.follow()
diff --git a/tests/oidc/test_dynamic_client_registration_management.py b/tests/oidc/test_dynamic_client_registration_management.py
index 3e6bd3f5..71934db5 100644
--- a/tests/oidc/test_dynamic_client_registration_management.py
+++ b/tests/oidc/test_dynamic_client_registration_management.py
@@ -146,7 +146,7 @@ def test_delete(testclient, backend, user):
     ]
 
     client = models.Client(client_id="foobar", client_name="Some client")
-    client.save()
+    backend.save(client)
 
     headers = {"Authorization": "Bearer static-token"}
     with warnings.catch_warnings(record=True):
diff --git a/tests/oidc/test_implicit_flow.py b/tests/oidc/test_implicit_flow.py
index ba1a08ab..dd3f5aba 100644
--- a/tests/oidc/test_implicit_flow.py
+++ b/tests/oidc/test_implicit_flow.py
@@ -10,7 +10,7 @@ def test_oauth_implicit(testclient, user, client, backend):
     client.grant_types = ["token"]
     client.token_endpoint_auth_method = "none"
 
-    client.save()
+    backend.save(client)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -48,14 +48,14 @@ def test_oauth_implicit(testclient, user, client, backend):
 
     client.grant_types = ["code"]
     client.token_endpoint_auth_method = "client_secret_basic"
-    client.save()
+    backend.save(client)
 
 
 def test_oidc_implicit(testclient, keypair, user, client, trusted_client, backend):
     client.grant_types = ["token id_token"]
     client.token_endpoint_auth_method = "none"
 
-    client.save()
+    backend.save(client)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -101,7 +101,7 @@ def test_oidc_implicit(testclient, keypair, user, client, trusted_client, backen
 
     client.grant_types = ["code"]
     client.token_endpoint_auth_method = "client_secret_basic"
-    client.save()
+    backend.save(client)
 
 
 def test_oidc_implicit_with_group(
@@ -110,7 +110,7 @@ def test_oidc_implicit_with_group(
     client.grant_types = ["token id_token"]
     client.token_endpoint_auth_method = "none"
 
-    client.save()
+    backend.save(client)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -157,4 +157,4 @@ def test_oidc_implicit_with_group(
 
     client.grant_types = ["code"]
     client.token_endpoint_auth_method = "client_secret_basic"
-    client.save()
+    backend.save(client)
diff --git a/tests/oidc/test_password_flow.py b/tests/oidc/test_password_flow.py
index daaad5d3..725f1503 100644
--- a/tests/oidc/test_password_flow.py
+++ b/tests/oidc/test_password_flow.py
@@ -33,7 +33,7 @@ def test_password_flow_basic(testclient, user, client, backend):
 
 def test_password_flow_post(testclient, user, client, backend):
     client.token_endpoint_auth_method = "client_secret_post"
-    client.save()
+    backend.save(client)
 
     res = testclient.post(
         "/oauth/token",
diff --git a/tests/oidc/test_refresh_token.py b/tests/oidc/test_refresh_token.py
index 7a99bcd7..a0516a5d 100644
--- a/tests/oidc/test_refresh_token.py
+++ b/tests/oidc/test_refresh_token.py
@@ -82,7 +82,7 @@ def test_refresh_token_with_invalid_user(testclient, client, backend):
         emails=["temp@temp.com"],
         password="correct horse battery staple",
     )
-    user.save()
+    backend.save(user)
 
     res = testclient.get(
         "/oauth/authorize",
@@ -137,7 +137,9 @@ def test_refresh_token_with_invalid_user(testclient, client, backend):
     backend.get(models.Token, access_token=access_token).delete()
 
 
-def test_cannot_refresh_token_for_locked_users(testclient, logged_user, client):
+def test_cannot_refresh_token_for_locked_users(
+    testclient, logged_user, client, backend
+):
     """Canaille should not issue new tokens for locked users."""
     res = testclient.get(
         "/oauth/authorize",
@@ -167,7 +169,7 @@ def test_cannot_refresh_token_for_locked_users(testclient, logged_user, client):
     )
 
     logged_user.lock_date = datetime.datetime.now(datetime.timezone.utc)
-    logged_user.save()
+    backend.save(logged_user)
 
     res = testclient.post(
         "/oauth/token",
diff --git a/tests/oidc/test_token_admin.py b/tests/oidc/test_token_admin.py
index 7eca4e9c..24136136 100644
--- a/tests/oidc/test_token_admin.py
+++ b/tests/oidc/test_token_admin.py
@@ -18,7 +18,7 @@ def test_token_list(testclient, token, logged_admin):
     res.mustcontain(token.token_id)
 
 
-def test_token_list_pagination(testclient, logged_admin, client):
+def test_token_list_pagination(testclient, logged_admin, client, backend):
     res = testclient.get("/admin/token")
     res.mustcontain("0 items")
     tokens = []
@@ -36,7 +36,7 @@ def test_token_list_pagination(testclient, logged_admin, client):
             ),
             lifetime=3600,
         )
-        token.save()
+        backend.save(token)
         tokens.append(token)
 
     res = testclient.get("/admin/token")
@@ -74,7 +74,7 @@ def test_token_list_bad_pages(testclient, logged_admin):
     )
 
 
-def test_token_list_search(testclient, logged_admin, client):
+def test_token_list_search(testclient, logged_admin, client, backend):
     token1 = models.Token(
         token_id=gen_salt(48),
         access_token="this-token-is-ok",
@@ -88,7 +88,7 @@ def test_token_list_search(testclient, logged_admin, client):
         ),
         lifetime=3600,
     )
-    token1.save()
+    backend.save(token1)
     token2 = models.Token(
         token_id=gen_salt(48),
         access_token="this-token-is-valid",
@@ -102,7 +102,7 @@ def test_token_list_search(testclient, logged_admin, client):
         ),
         lifetime=3600,
     )
-    token2.save()
+    backend.save(token2)
 
     res = testclient.get("/admin/token")
     res.mustcontain("2 items")
diff --git a/tests/oidc/test_token_revocation.py b/tests/oidc/test_token_revocation.py
index fe119f66..193613ae 100644
--- a/tests/oidc/test_token_revocation.py
+++ b/tests/oidc/test_token_revocation.py
@@ -63,11 +63,11 @@ def test_revoke_refresh_token_with_hint(testclient, user, client, token):
     assert token.revokation_date
 
 
-def test_cannot_refresh_after_revocation(testclient, user, client, token):
+def test_cannot_refresh_after_revocation(testclient, user, client, token, backend):
     token.revokation_date = datetime.datetime.now(
         datetime.timezone.utc
     ) - datetime.timedelta(days=7)
-    token.save()
+    backend.save(token)
 
     res = testclient.post(
         "/oauth/token",
diff --git a/tests/oidc/test_userinfo.py b/tests/oidc/test_userinfo.py
index f7744a89..5a3cfca1 100644
--- a/tests/oidc/test_userinfo.py
+++ b/tests/oidc/test_userinfo.py
@@ -146,9 +146,9 @@ def test_generate_user_claims(user, foo_group):
     }
 
 
-def test_userinfo(testclient, token, user, foo_group):
+def test_userinfo(testclient, token, user, foo_group, backend):
     token.scope = ["openid"]
-    token.save()
+    backend.save(token)
     testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -156,7 +156,7 @@ def test_userinfo(testclient, token, user, foo_group):
     )
 
     token.scope = ["openid", "profile"]
-    token.save()
+    backend.save(token)
     res = testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -172,7 +172,7 @@ def test_userinfo(testclient, token, user, foo_group):
     }
 
     token.scope = ["openid", "profile", "email"]
-    token.save()
+    backend.save(token)
     res = testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -189,7 +189,7 @@ def test_userinfo(testclient, token, user, foo_group):
     }
 
     token.scope = ["openid", "profile", "address"]
-    token.save()
+    backend.save(token)
     res = testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -206,7 +206,7 @@ def test_userinfo(testclient, token, user, foo_group):
     }
 
     token.scope = ["openid", "profile", "phone"]
-    token.save()
+    backend.save(token)
     res = testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -223,7 +223,7 @@ def test_userinfo(testclient, token, user, foo_group):
     }
 
     token.scope = ["openid", "profile", "groups"]
-    token.save()
+    backend.save(token)
     res = testclient.get(
         "/oauth/userinfo",
         headers={"Authorization": f"Bearer {token.access_token}"},
@@ -296,7 +296,7 @@ def test_claim_is_omitted_if_empty(testclient, backend, user):
     # According to https://openid.net/specs/openid-connect-core-1_0.html#UserInfoResponse
     # it's better to not insert a null or empty string value
     user.emails = []
-    user.save()
+    backend.save(user)
 
     default_jwt_mapping = JWTSettings().model_dump()
     data = generate_user_claims(user, STANDARD_CLAIMS, default_jwt_mapping)