diff --git a/netbox/netbox/authentication.py b/netbox/netbox/authentication/__init__.py
similarity index 98%
rename from netbox/netbox/authentication.py
rename to netbox/netbox/authentication/__init__.py
index 2b66639c8..55fd91d4d 100644
--- a/netbox/netbox/authentication.py
+++ b/netbox/netbox/authentication/__init__.py
@@ -14,6 +14,7 @@ from users.models import Group, ObjectPermission
 from utilities.permissions import (
     permission_is_exempt, qs_filter_from_constraints, resolve_permission, resolve_permission_type,
 )
+from .misc import _mirror_groups
 
 UserModel = get_user_model()
 
@@ -313,7 +314,7 @@ class RemoteUserBackend(_RemoteUserBackend):
 
 # Create a new instance of django-auth-ldap's LDAPBackend with our own ObjectPermissions
 try:
-    from django_auth_ldap.backend import LDAPBackend as LDAPBackend_
+    from django_auth_ldap.backend import _LDAPUser, LDAPBackend as LDAPBackend_
 
     class NBLDAPBackend(ObjectPermissionMixin, LDAPBackend_):
         def get_permission_filter(self, user_obj):
@@ -323,6 +324,10 @@ try:
                     hasattr(user_obj.ldap_user, "group_names")):
                 permission_filter = permission_filter | Q(groups__name__in=user_obj.ldap_user.group_names)
             return permission_filter
+
+    # Patch with our modified _mirror_groups() method to support our custom Group model
+    _LDAPUser._mirror_groups = _mirror_groups
+
 except ModuleNotFoundError:
     pass
 
diff --git a/netbox/netbox/authentication/misc.py b/netbox/netbox/authentication/misc.py
new file mode 100644
index 000000000..fe89b8e39
--- /dev/null
+++ b/netbox/netbox/authentication/misc.py
@@ -0,0 +1,67 @@
+# Copyright (c) 2009, Peter Sagerson
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# - Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# - Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+from users.models import Group
+
+
+# Copied from django_auth_ldap.backend._LDAPUser and modified to support our
+# custom Group model.
+def _mirror_groups(self):
+    """
+    Mirrors the user's LDAP groups in the Django database and updates the
+    user's membership.
+    """
+    target_group_names = frozenset(self._get_groups().get_group_names())
+    current_group_names = frozenset(
+        self._user.groups.values_list("name", flat=True).iterator()
+    )
+
+    # These were normalized to sets above.
+    MIRROR_GROUPS_EXCEPT = self.settings.MIRROR_GROUPS_EXCEPT
+    MIRROR_GROUPS = self.settings.MIRROR_GROUPS
+
+    # If the settings are white- or black-listing groups, we'll update
+    # target_group_names such that we won't modify the membership of groups
+    # beyond our purview.
+    if isinstance(MIRROR_GROUPS_EXCEPT, (set, frozenset)):
+        target_group_names = (target_group_names - MIRROR_GROUPS_EXCEPT) | (
+            current_group_names & MIRROR_GROUPS_EXCEPT
+        )
+    elif isinstance(MIRROR_GROUPS, (set, frozenset)):
+        target_group_names = (target_group_names & MIRROR_GROUPS) | (
+            current_group_names - MIRROR_GROUPS
+        )
+
+    if target_group_names != current_group_names:
+        existing_groups = list(
+            Group.objects.filter(name__in=target_group_names).iterator()
+        )
+        existing_group_names = frozenset(group.name for group in existing_groups)
+
+        new_groups = [
+            Group.objects.get_or_create(name=name)[0]
+            for name in target_group_names
+            if name not in existing_group_names
+        ]
+
+        self._user.groups.set(existing_groups + new_groups)