diff --git a/AUTHORS b/AUTHORS
index 463b917..8e10a46 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -17,3 +17,4 @@ ADDITIONAL CONTRIBUTORS include:
     * Jaap Roes
     * Ed Davison
     * Sander Smits
+    * Steve Kowalik
diff --git a/setup.cfg b/setup.cfg
index 8257a20..0d2a4f5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -26,7 +26,7 @@ package_dir = =src
 python_requires = >=3.8
 install_requires =
     Django >= 2.2
-    lockfile >= 0.8
+    filelock >= 3.5
 
 [options.packages.find]
 where = src
diff --git a/src/mailer/engine.py b/src/mailer/engine.py
index 2abe8d9..c9c3fed 100644
--- a/src/mailer/engine.py
+++ b/src/mailer/engine.py
@@ -4,7 +4,6 @@
 import time
 from socket import error as socket_error
 
-import lockfile
 from django import VERSION as DJANGO_VERSION
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
@@ -13,6 +12,7 @@
 from django.core.mail.utils import DNS_NAME
 from django.db import DatabaseError, NotSupportedError, OperationalError, transaction
 from django.utils.module_loading import import_string
+import filelock
 
 from mailer.models import RESULT_FAILURE, RESULT_SUCCESS, Message, MessageLog, get_message_id
 
@@ -153,14 +153,15 @@ def acquire_lock():
     else:
         lock_file_path = "send_mail"
 
-    lock = lockfile.FileLock(lock_file_path)
+    lock = filelock.FileLock(lock_file_path)
 
-    try:
-        lock.acquire(LOCK_WAIT_TIMEOUT)
-    except lockfile.AlreadyLocked:
+    if lock.is_locked:
         logger.error("lock already in place. quitting.")
         return False, lock
-    except lockfile.LockTimeout:
+
+    try:
+        lock.acquire(timeout=LOCK_WAIT_TIMEOUT)
+    except filelock.Timeout:
         logger.error("waiting for the lock timed out. quitting.")
         return False, lock
     logger.debug("acquired.")
diff --git a/tests/test_mailer.py b/tests/test_mailer.py
index d6763c6..ef51cd4 100644
--- a/tests/test_mailer.py
+++ b/tests/test_mailer.py
@@ -4,7 +4,7 @@
 from unittest.mock import Mock, PropertyMock, patch
 
 import django
-import lockfile
+import filelock
 import mailer
 from django.core import mail
 from django.core.exceptions import ImproperlyConfigured
@@ -438,8 +438,10 @@ class CustomError(Exception):
         self.CustomError = CustomError
 
         self.lock_mock = Mock()
+        is_locked = PropertyMock(return_value=False)
+        type(self.lock_mock).is_locked = is_locked
 
-        self.patcher_lock = patch("lockfile.FileLock", return_value=self.lock_mock)
+        self.patcher_lock = patch("filelock.FileLock", return_value=self.lock_mock)
         self.patcher_prio = patch("mailer.engine.prioritize", side_effect=CustomError)
 
         self.lock = self.patcher_lock.start()
@@ -447,7 +449,7 @@ class CustomError(Exception):
 
     def test(self):
         self.assertRaises(self.CustomError, engine.send_all)
-        self.lock_mock.acquire.assert_called_once_with(engine.LOCK_WAIT_TIMEOUT)
+        self.lock_mock.acquire.assert_called_once_with(timeout=engine.LOCK_WAIT_TIMEOUT)
         self.lock.assert_called_once_with("send_mail")
         self.prio.assert_called_once()
 
@@ -458,12 +460,11 @@ def tearDown(self):
 
 class LockLockedTest(TestCase):
     def setUp(self):
-        config = {
-            "acquire.side_effect": lockfile.AlreadyLocked,
-        }
-        self.lock_mock = Mock(**config)
+        lock_mock = Mock()
+        self.is_locked = PropertyMock(return_value=True)
+        type(lock_mock).is_locked = self.is_locked
 
-        self.patcher_lock = patch("lockfile.FileLock", return_value=self.lock_mock)
+        self.patcher_lock = patch("filelock.FileLock", return_value=lock_mock)
         self.patcher_prio = patch("mailer.engine.prioritize", side_effect=Exception)
 
         self.lock = self.patcher_lock.start()
@@ -471,8 +472,7 @@ def setUp(self):
 
     def test(self):
         engine.send_all()
-        self.lock_mock.acquire.assert_called_once_with(engine.LOCK_WAIT_TIMEOUT)
-        self.lock.assert_called_once_with("send_mail")
+        self.is_locked.assert_called_once_with()
         self.prio.assert_not_called()
 
     def tearDown(self):
@@ -483,11 +483,13 @@ def tearDown(self):
 class LockTimeoutTest(TestCase):
     def setUp(self):
         config = {
-            "acquire.side_effect": lockfile.LockTimeout,
+            "acquire.side_effect": filelock.Timeout("send_mail"),
         }
         self.lock_mock = Mock(**config)
+        is_locked = PropertyMock(return_value=False)
+        type(self.lock_mock).is_locked = is_locked
 
-        self.patcher_lock = patch("lockfile.FileLock", return_value=self.lock_mock)
+        self.patcher_lock = patch("filelock.FileLock", return_value=self.lock_mock)
         self.patcher_prio = patch("mailer.engine.prioritize", side_effect=Exception)
 
         self.lock = self.patcher_lock.start()
@@ -495,7 +497,7 @@ def setUp(self):
 
     def test(self):
         engine.send_all()
-        self.lock_mock.acquire.assert_called_once_with(engine.LOCK_WAIT_TIMEOUT)
+        self.lock_mock.acquire.assert_called_once_with(timeout=engine.LOCK_WAIT_TIMEOUT)
         self.lock.assert_called_once_with("send_mail")
         self.prio.assert_not_called()
 
diff --git a/tox.ini b/tox.ini
index 83aff4e..2dbd80d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -6,6 +6,7 @@ envlist =
     py39-django{30,31,32,40}-test,
     py310-django{40,41,42}-test,
     py311-django42-test,
+    py312-django42-test,
     flake-py39-django32,
     checkmanifest-py39,
 
@@ -15,6 +16,7 @@ basepython =
     py39: python3.9
     py310: python3.10
     py311: python3.11
+    py312: python3.12
 
 commands =
     test: pytest --cov=mailer