diff --git a/config b/config
index cee373d3..61008501 100644
--- a/config
+++ b/config
@@ -93,8 +93,14 @@
 # Path of the file containing password of the reader DN
 #ldap_secret_file = /run/secrets/ldap_password
 
-# the attribute to read the group memberships from in the user's LDAP entry (default: not set)
-#ldap_groups_attribute = memberOf
+# The attribute in user entry to read the group memberships.
+#ldap_groups_attribute =
+
+# The attribute in group entries to read the group memberships.
+#ldap_group_members_attribute =
+
+# The base dn to find the groups. Necessary only if ldap_group_members_attribute is defined and other then ldap_base.
+#ldap_groups_base =
 
 # The filter to find the DN of the user. This filter must contain a python-style placeholder for the login
 #ldap_filter = (&(objectClass=person)(uid={0}))
diff --git a/radicale/app/proppatch.py b/radicale/app/proppatch.py
index 76b4a1a1..c894850c 100644
--- a/radicale/app/proppatch.py
+++ b/radicale/app/proppatch.py
@@ -27,7 +27,6 @@ from http import client
 from typing import Dict, Optional, cast
 
 import defusedxml.ElementTree as DefusedET
-
 import radicale.item as radicale_item
 from radicale import httputils, storage, types, xmlutils
 from radicale.app.base import Access, ApplicationBase
diff --git a/radicale/auth/htpasswd.py b/radicale/auth/htpasswd.py
index dd66dfbd..0615dcbb 100644
--- a/radicale/auth/htpasswd.py
+++ b/radicale/auth/htpasswd.py
@@ -60,7 +60,6 @@ import time
 from typing import Any, Tuple
 
 from passlib.hash import apr_md5_crypt, sha256_crypt, sha512_crypt
-
 from radicale import auth, config, logger
 
 
diff --git a/radicale/auth/ldap.py b/radicale/auth/ldap.py
index e45aeb29..2e6635b6 100644
--- a/radicale/auth/ldap.py
+++ b/radicale/auth/ldap.py
@@ -18,13 +18,14 @@
 Authentication backend that checks credentials with a LDAP server.
 Following parameters are needed in the configuration:
    ldap_uri            The LDAP URL to the server like ldap://localhost
-   ldap_base           The baseDN of the LDAP server
+   ldap_base           The baseDN of the LDAP server searching for users.
    ldap_reader_dn      The DN of a LDAP user with read access to get the user accounts
    ldap_secret         The password of the ldap_reader_dn
    ldap_secret_file    The path of the file containing the password of the ldap_reader_dn
    ldap_filter         The search filter to find the user to authenticate by the username
    ldap_user_attribute The attribute to be used as username after authentication
    ldap_groups_attribute The attribute containing group memberships in the LDAP user entry
+   ldap_groups_base    The baseDN of the LDAP server searching for groups.
 Following parameters controls SSL connections:
    ldap_use_ssl        If ssl encryption should be used (to be deprecated)
    ldap_security    The encryption mode to be used: *none*|tls|starttls
@@ -78,6 +79,10 @@ class Auth(auth.BaseAuth):
         self._ldap_filter = configuration.get("auth", "ldap_filter")
         self._ldap_user_attr = configuration.get("auth", "ldap_user_attribute")
         self._ldap_groups_attr = configuration.get("auth", "ldap_groups_attribute")
+        self._ldap_group_members_attr = configuration.get("auth", "ldap_group_members_attribute")
+        self._ldap_groups_base = configuration.get("auth", "ldap_groups_base")
+        if self._ldap_groups_base == "":
+            self._ldap_groups_base = self._ldap_base
         ldap_secret_file_path = configuration.get("auth", "ldap_secret_file")
         if ldap_secret_file_path:
             with open(ldap_secret_file_path, 'r') as file:
@@ -172,17 +177,25 @@ class Auth(auth.BaseAuth):
             conn.set_option(self.ldap.OPT_REFERRALS, 0)
             conn.simple_bind_s(user_dn, password)
             tmp: list[str] = []
+            gdns: list[str] = []
             if self._ldap_groups_attr:
-                tmp = []
-                for g in user_entry[1][self._ldap_groups_attr]:
-                    """Get group g's RDN's attribute value"""
-                    try:
-                        rdns = self.ldap.dn.explode_dn(g, notypes=True)
-                        tmp.append(rdns[0])
-                    except Exception:
-                        tmp.append(g.decode('utf8'))
-                self._ldap_groups = set(tmp)
-                logger.debug("_login2 LDAP groups of user: %s", ",".join(self._ldap_groups))
+                gdns = user_entry[1][self._ldap_groups_attr]
+            elif self._ldap_group_members_attr:
+                res = conn.search_s(
+                    self._ldap_groups_base,
+                    self.ldap.SCOPE_SUBTREE,
+                    filterstr="({0}={1})".format(self._ldap_group_members_attr,user_dn),
+                    attrlist=self._ldap_attributes
+                )
+            for g in gdns:
+                """Get group g's RDN's attribute value"""
+                try:
+                    rdns = self.ldap.dn.explode_dn(g, notypes=True)
+                    tmp.append(rdns[0])
+                except Exception:
+                    tmp.append(g.decode('utf8'))
+            self._ldap_groups = set(tmp)
+            logger.debug("_login2 LDAP groups of user: %s", ",".join(self._ldap_groups))
             if self._ldap_user_attr:
                 if user_entry[1][self._ldap_user_attr]:
                     tmplogin = user_entry[1][self._ldap_user_attr][0]
@@ -261,17 +274,28 @@ class Auth(auth.BaseAuth):
                 logger.debug(f"_login3 user '{login}' cannot be found")
                 return ""
             tmp: list[str] = []
+            gdns: list[str] = []
+            """Let's collect the groups of the user."""
             if self._ldap_groups_attr:
-                tmp = []
-                for g in user_entry['attributes'][self._ldap_groups_attr]:
-                    """Get group g's RDN's attribute value"""
-                    try:
-                        rdns = self.ldap3.utils.dn.parse_dn(g)
-                        tmp.append(rdns[0][1])
-                    except Exception:
-                        tmp.append(g)
-                self._ldap_groups = set(tmp)
-                logger.debug("_login3 LDAP groups of user: %s", ",".join(self._ldap_groups))
+                gdns = user_entry['attributes'][self._ldap_groups_attr]
+            elif self._ldap_group_members_attr:
+                conn.search(
+                    search_base=self._ldap_groups_base,
+                    search_filter="({0}={1})".format(self._ldap_group_members_attr,user_dn),
+                    search_scope=self.ldap3.SUBTREE,
+                    attributes="dn"
+                )
+                for group in conn.response:
+                    gdns.append(group['dn'])
+            for g in gdns:
+                """Get group g's RDN's attribute value"""
+                try:
+                    rdns = self.ldap3.utils.dn.parse_dn(g)
+                    tmp.append(rdns[0][1])
+                except Exception:
+                    tmp.append(g)
+            self._ldap_groups = set(tmp)
+            logger.debug("_login3 LDAP groups of user: %s", ",".join(self._ldap_groups))
             if self._ldap_user_attr:
                 if user_entry['attributes'][self._ldap_user_attr]:
                     if isinstance(user_entry['attributes'][self._ldap_user_attr], list):
diff --git a/radicale/config.py b/radicale/config.py
index c4f5fbe7..90b3a9d5 100644
--- a/radicale/config.py
+++ b/radicale/config.py
@@ -269,31 +269,39 @@ DEFAULT_CONFIG_SCHEMA: types.CONFIG_SCHEMA = OrderedDict([
             "type": str}),
         ("ldap_base", {
             "value": "",
-            "help": "LDAP base DN of the ldap server",
+            "help": "The base DN of the ldap server where the user can be find.",
             "type": str}),
         ("ldap_reader_dn", {
             "value": "",
-            "help": "the DN of a ldap user with read access to get the user accounts",
+            "help": "The DN of a ldap user with read access to get the user accounts",
             "type": str}),
         ("ldap_secret", {
             "value": "",
-            "help": "the password of the ldap_reader_dn",
+            "help": "The password of the ldap_reader_dn",
             "type": str}),
         ("ldap_secret_file", {
             "value": "",
-            "help": "path of the file containing the password of the ldap_reader_dn",
+            "help": "Path of the file containing the password of the ldap_reader_dn",
             "type": str}),
         ("ldap_filter", {
             "value": "(cn={0})",
-            "help": "the search filter to find the user DN to authenticate by the username",
+            "help": "The search filter to find the user DN to authenticate by the username",
             "type": str}),
         ("ldap_user_attribute", {
             "value": "",
-            "help": "the attribute to be used as username after authentication",
+            "help": "The attribute to be used as username after authentication",
             "type": str}),
         ("ldap_groups_attribute", {
             "value": "",
-            "help": "attribute to read the group memberships from",
+            "help": "Attribute in the user entry to read the group memberships from.",
+            "type": str}),
+        ("ldap_group_members_attribute", {
+            "value": "",
+            "help": "Attribute in the group entries to read the group memberships from.",
+            "type": str}),
+        ("ldap_groups_base_dn", {
+            "value": "",
+            "help": "The base dn to find the groups. Necessary only if ldap_group_members_attribute is defined and other then ldap_base.",
             "type": str}),
         ("ldap_use_ssl", {
             "value": "False",
diff --git a/radicale/hook/rabbitmq/__init__.py b/radicale/hook/rabbitmq/__init__.py
index 2323ed43..5b1ec659 100644
--- a/radicale/hook/rabbitmq/__init__.py
+++ b/radicale/hook/rabbitmq/__init__.py
@@ -1,6 +1,5 @@
 import pika
 from pika.exceptions import ChannelWrongStateError, StreamLostError
-
 from radicale import hook
 from radicale.hook import HookNotificationItem
 from radicale.log import logger
diff --git a/radicale/tests/__init__.py b/radicale/tests/__init__.py
index e5ecb1f9..23df6d54 100644
--- a/radicale/tests/__init__.py
+++ b/radicale/tests/__init__.py
@@ -31,9 +31,9 @@ from io import BytesIO
 from typing import Any, Dict, List, Optional, Tuple, Union
 from urllib.parse import quote
 
-import defusedxml.ElementTree as DefusedET
 import vobject
 
+import defusedxml.ElementTree as DefusedET
 import radicale
 from radicale import app, config, types, xmlutils
 
diff --git a/radicale/tests/test_auth.py b/radicale/tests/test_auth.py
index 88cd3ea4..9036c500 100644
--- a/radicale/tests/test_auth.py
+++ b/radicale/tests/test_auth.py
@@ -29,7 +29,6 @@ import sys
 from typing import Iterable, Tuple, Union
 
 import pytest
-
 from radicale import xmlutils
 from radicale.tests import BaseTest
 
diff --git a/radicale/tests/test_base.py b/radicale/tests/test_base.py
index d2b26949..8cd3279a 100644
--- a/radicale/tests/test_base.py
+++ b/radicale/tests/test_base.py
@@ -26,9 +26,9 @@ import os
 import posixpath
 from typing import Any, Callable, ClassVar, Iterable, List, Optional, Tuple
 
-import defusedxml.ElementTree as DefusedET
 import vobject
 
+import defusedxml.ElementTree as DefusedET
 from radicale import storage, xmlutils
 from radicale.tests import RESPONSES, BaseTest
 from radicale.tests.helpers import get_file_content
diff --git a/radicale/tests/test_config.py b/radicale/tests/test_config.py
index 92ece9a6..7b46a601 100644
--- a/radicale/tests/test_config.py
+++ b/radicale/tests/test_config.py
@@ -21,7 +21,6 @@ from configparser import RawConfigParser
 from typing import List, Tuple
 
 import pytest
-
 from radicale import config, types
 from radicale.tests.helpers import configuration_to_dict
 
diff --git a/radicale/tests/test_server.py b/radicale/tests/test_server.py
index b344dddf..d1887b63 100644
--- a/radicale/tests/test_server.py
+++ b/radicale/tests/test_server.py
@@ -34,7 +34,6 @@ from urllib import request
 from urllib.error import HTTPError, URLError
 
 import pytest
-
 from radicale import config, server
 from radicale.tests import BaseTest
 from radicale.tests.helpers import configuration_to_dict, get_file_path
diff --git a/radicale/tests/test_storage.py b/radicale/tests/test_storage.py
index 89572bca..53dc1669 100644
--- a/radicale/tests/test_storage.py
+++ b/radicale/tests/test_storage.py
@@ -26,7 +26,6 @@ import shutil
 from typing import ClassVar, cast
 
 import pytest
-
 import radicale.tests.custom.storage_simple_sync
 from radicale.tests import BaseTest
 from radicale.tests.helpers import get_file_content