diff --git a/api/app/settings/common.py b/api/app/settings/common.py
index 2f1e468eb4d3..156f3f1b4a95 100644
--- a/api/app/settings/common.py
+++ b/api/app/settings/common.py
@@ -804,10 +804,10 @@
     # FE uri to redirect user to from activation email
     "ACTIVATION_URL": "activate/{uid}/{token}",
     # register or activation endpoint will send confirmation email to user
+    "LOGIN_FIELD": "email",
     "SEND_CONFIRMATION_EMAIL": False,
     "SERIALIZERS": {
         "token": "custom_auth.serializers.CustomTokenSerializer",
-        "token_create": "custom_auth.serializers.CustomTokenCreateSerializer",
         "user_create": "custom_auth.serializers.CustomUserCreateSerializer",
         "user_delete": "custom_auth.serializers.CustomUserDelete",
         "current_user": "users.serializers.CustomCurrentUserSerializer",
@@ -1153,8 +1153,9 @@
 LDAP_INSTALLED = importlib.util.find_spec("flagsmith_ldap")
 # The URL of the LDAP server.
 LDAP_AUTH_URL = env.str("LDAP_AUTH_URL", None)
+LDAP_ENABLED = LDAP_INSTALLED and LDAP_AUTH_URL
 
-if LDAP_INSTALLED and LDAP_AUTH_URL:  # pragma: no cover
+if LDAP_ENABLED:  # pragma: no cover
     AUTHENTICATION_BACKENDS.insert(0, "django_python3_ldap.auth.LDAPBackend")
     INSTALLED_APPS.append("flagsmith_ldap")
 
@@ -1227,7 +1228,6 @@
     # The LDAP user username and password used by `sync_ldap_users_and_groups` command
     LDAP_SYNC_USER_USERNAME = env.str("LDAP_SYNC_USER_USERNAME", None)
     LDAP_SYNC_USER_PASSWORD = env.str("LDAP_SYNC_USER_PASSWORD", None)
-    DJOSER["LOGIN_FIELD"] = "username"
 
 SEGMENT_CONDITION_VALUE_LIMIT = env.int("SEGMENT_CONDITION_VALUE_LIMIT", default=1000)
 if not 0 <= SEGMENT_CONDITION_VALUE_LIMIT < 2000000:
diff --git a/api/custom_auth/serializers.py b/api/custom_auth/serializers.py
index d1322c1d50be..238fe17adb96 100644
--- a/api/custom_auth/serializers.py
+++ b/api/custom_auth/serializers.py
@@ -1,8 +1,7 @@
 from typing import Any
 
 from django.conf import settings
-from djoser.conf import settings as djoser_settings
-from djoser.serializers import TokenCreateSerializer, UserCreateSerializer
+from djoser.serializers import UserCreateSerializer
 from rest_framework import serializers
 from rest_framework.authtoken.models import Token
 from rest_framework.exceptions import PermissionDenied
@@ -20,33 +19,6 @@
 )
 
 
-class CustomTokenCreateSerializer(TokenCreateSerializer):
-    """
-    NOTE: Some authentication backends (e.g., LDAP) support only
-    username and password authentication. However, the front-end
-    currently sends the email as the login key. To accommodate
-    this, we override the serializer to rename the username field
-    to the email (or any other field configurable using djoser settings) field.
-
-    """
-
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-        if djoser_settings.LOGIN_FIELD != FFAdminUser.USERNAME_FIELD:
-            # Because djoser have created a field named username(djoser_settings.LOGIN_FIELD) in the serializer
-            # We have to remove this and add the email(FFAdminUser.USERNAME_FIELD) field back
-            self.fields.pop(djoser_settings.LOGIN_FIELD)
-            self.fields[FFAdminUser.USERNAME_FIELD] = serializers.CharField(
-                required=False
-            )
-
-    def validate(self, attrs):
-        if djoser_settings.LOGIN_FIELD != FFAdminUser.USERNAME_FIELD:
-            attrs[djoser_settings.LOGIN_FIELD] = attrs.pop(FFAdminUser.USERNAME_FIELD)
-
-        return super().validate(attrs)
-
-
 class CustomTokenSerializer(serializers.ModelSerializer):
     class Meta:
         model = Token
diff --git a/api/poetry.lock b/api/poetry.lock
index 85b3b132af1a..379fbfc7f6c6 100644
--- a/api/poetry.lock
+++ b/api/poetry.lock
@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 1.8.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 1.8.5 and should not be changed by hand.
 
 [[package]]
 name = "annotated-types"
@@ -1126,13 +1126,13 @@ test = ["cryptography", "freezegun", "pytest", "pytest-cov", "pytest-django", "p
 
 [[package]]
 name = "djoser"
-version = "2.2.2"
+version = "2.3.0"
 description = "REST implementation of Django authentication system."
 optional = false
-python-versions = ">=3.8,<4.0"
+python-versions = "<4.0,>=3.8"
 files = [
-    {file = "djoser-2.2.2-py3-none-any.whl", hash = "sha256:efb91ad61e4d5b8d664db029b5947df9d34078289ef2680a1ab665e047144b74"},
-    {file = "djoser-2.2.2.tar.gz", hash = "sha256:9deb831a1c8781ceff325699e1407b4e1be8b4588e87071621d88ba31c09349f"},
+    {file = "djoser-2.3.0-py3-none-any.whl", hash = "sha256:6af76cb8d73f8a879ab417c1251f5aa0242c4e3c4a8fee3a6393f1126874b269"},
+    {file = "djoser-2.3.0.tar.gz", hash = "sha256:c46e4b609348b824ba138aba914ca8a89bb42b7d23975c34e2702ea04b13c989"},
 ]
 
 [package.dependencies]
@@ -3353,6 +3353,7 @@ files = [
     {file = "PyYAML-6.0.1-cp311-cp311-win_amd64.whl", hash = "sha256:bf07ee2fef7014951eeb99f56f39c9bb4af143d8aa3c21b1677805985307da34"},
     {file = "PyYAML-6.0.1-cp312-cp312-macosx_10_9_x86_64.whl", hash = "sha256:855fb52b0dc35af121542a76b9a84f8d1cd886ea97c84703eaa6d88e37a2ad28"},
     {file = "PyYAML-6.0.1-cp312-cp312-macosx_11_0_arm64.whl", hash = "sha256:40df9b996c2b73138957fe23a16a4f0ba614f4c0efce1e9406a184b6d07fa3a9"},
+    {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:a08c6f0fe150303c1c6b71ebcd7213c2858041a7e01975da3a99aed1e7a378ef"},
     {file = "PyYAML-6.0.1-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:6c22bec3fbe2524cde73d7ada88f6566758a8f7227bfbf93a408a9d86bcc12a0"},
     {file = "PyYAML-6.0.1-cp312-cp312-musllinux_1_1_x86_64.whl", hash = "sha256:8d4e9c88387b0f5c7d5f281e55304de64cf7f9c0021a3525bd3b1c542da3b0e4"},
     {file = "PyYAML-6.0.1-cp312-cp312-win32.whl", hash = "sha256:d483d2cdf104e7c9fa60c544d92981f12ad66a457afae824d146093b8c294c54"},
@@ -4216,4 +4217,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.11, <3.13"
-content-hash = "3a490ddf78d714b0fb4394a3f384856576d1db5b5c9ad270a29d1434aa2562f6"
+content-hash = "2b81530cb56fddb93c5bc5640ab3bbab2da3f0d273311b65317f9e4b202adcb0"
diff --git a/api/pyproject.toml b/api/pyproject.toml
index c808f8b6f967..56cf7f6f1e0c 100644
--- a/api/pyproject.toml
+++ b/api/pyproject.toml
@@ -153,7 +153,7 @@ pymemcache = "~4.0.0"
 google-re2 = "^1.0"
 django-softdelete = "~0.10.5"
 simplejson = "~3.19.1"
-djoser = "~2.2.2"
+djoser = "~2.3.0"
 django-storages = "~1.10.1"
 django-environ = "~0.4.5"
 influxdb-client = "~1.28.0"
diff --git a/api/tests/unit/custom_auth/test_unit_custom_auth_serializer.py b/api/tests/unit/custom_auth/test_unit_custom_auth_serializer.py
index 922cff3a133f..37872a8e9425 100644
--- a/api/tests/unit/custom_auth/test_unit_custom_auth_serializer.py
+++ b/api/tests/unit/custom_auth/test_unit_custom_auth_serializer.py
@@ -1,7 +1,9 @@
-from copy import deepcopy
+import typing
 
 import pytest
+from django.contrib.auth.models import AbstractUser
 from django.test import RequestFactory
+from djoser.serializers import TokenCreateSerializer
 from pytest_django.fixtures import SettingsWrapper
 from pytest_mock import MockerFixture
 from rest_framework.exceptions import PermissionDenied
@@ -9,10 +11,7 @@
 from custom_auth.constants import (
     USER_REGISTRATION_WITHOUT_INVITE_ERROR_MESSAGE,
 )
-from custom_auth.serializers import (
-    CustomTokenCreateSerializer,
-    CustomUserCreateSerializer,
-)
+from custom_auth.serializers import CustomUserCreateSerializer
 from organisations.invites.models import InviteLink
 from users.models import FFAdminUser, SignUpType
 
@@ -153,23 +152,44 @@ def test_invite_link_validation_mixin_validate_fails_if_invite_link_hash_not_val
     assert exc_info.value.detail == USER_REGISTRATION_WITHOUT_INVITE_ERROR_MESSAGE
 
 
-def test_CustomTokenCreateSerializer_validate_uses_login_field_to_authenticate(
-    settings: SettingsWrapper, mocker: MockerFixture
+@pytest.fixture
+def django_ldap_username_field(
+    django_user_model: type[AbstractUser],
+) -> typing.Generator[str, None, None]:
+    ldap_username_field = "username"
+    username_field = django_user_model.USERNAME_FIELD
+    django_user_model.USERNAME_FIELD = ldap_username_field
+    yield ldap_username_field
+    django_user_model.USERNAME_FIELD = username_field
+
+
+# Previously, Djoser's default `TokenCreateSerializer` only respected the
+# Djoser `LOGIN_FIELD` setting so it was impossible to grab the email from
+# serializer and send it as a username to the login backend — which is required for LDAP to work.
+# After Djoser 2.3.0, it's possible to alter `TokenCreateSerializer` behaviour
+# to support this by setting the Django user model's `USERNAME_FIELD` constant
+# to `"username"`, and Djoser's `LOGIN_FIELD` to `"email"`.
+# This test is here to make sure Djoser behaves as expected.
+def test_djoser_token_create_serializer__user_model_username_field__call_expected(
+    mocker: MockerFixture,
+    django_ldap_username_field: str,
 ) -> None:
     # Given
-    djoser_settings = deepcopy(settings.DJOSER)
-    djoser_settings["LOGIN_FIELD"] = "username"
-    settings.DJOSER = djoser_settings
+    expected_username = "some_username"
+    expected_password = "some_password"
 
     mocked_authenticate = mocker.patch("djoser.serializers.authenticate")
-    serializer = CustomTokenCreateSerializer(
-        data={"email": "some_username", "password": "some_password"}
+    serializer = TokenCreateSerializer(
+        data={"email": expected_username, "password": expected_password}
     )
+    expected_authenticate_kwargs = {
+        "request": None,
+        django_ldap_username_field: expected_username,
+        "password": expected_password,
+    }
 
     # When
     serializer.is_valid(raise_exception=True)
 
     # Then
-    mocked_authenticate.assert_called_with(
-        request=None, username="some_username", password="some_password"
-    )
+    mocked_authenticate.assert_called_with(**expected_authenticate_kwargs)
diff --git a/api/users/models.py b/api/users/models.py
index 2030ad05c3f7..2f0487a4592d 100644
--- a/api/users/models.py
+++ b/api/users/models.py
@@ -113,7 +113,7 @@ class FFAdminUser(LifecycleModel, AbstractUser):
 
     uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
 
-    USERNAME_FIELD = "email"
+    USERNAME_FIELD = "username" if settings.LDAP_ENABLED else "email"
     REQUIRED_FIELDS = ["first_name", "last_name", "sign_up_type"]
 
     class Meta: