diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index bdcd6df..6cbc765 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -13,13 +13,18 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13.0-rc.1"]
-        django-version: ["django==4.2.*", "django==5.0.*", "django==5.1.*", "django==5.2.*"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        django-version: ["django==4.2.*", "django==5.0.*", "django==5.1.*"]
         exclude:
-          - python-version: "3.12"
-            django-version: "django<4.2.8"
-          - python-version: "3.13.0-rc.1"
-            django-version: "django<5.2"
+          - python-version: "3.8"
+            django-version: "django==5.0.*"
+          - python-version: "3.8"
+            django-version: "django==5.1.*"
+          - python-version: "3.9"
+            django-version: "django==5.0.*"
+          - python-version: "3.9"
+            django-version: "django==5.1.*"
+
     steps:
       - uses: actions/checkout@v3
       - name: Set up Python ${{ matrix.python-version }}
@@ -29,10 +34,16 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r requirements_test.txt
+          pip install ${{ matrix.django-version }}
+          echo ${{ matrix.django-version }} >> dj.txt
+          pip install -c dj.txt -r requirements_test.txt
       - name: Lint with ruff
         run: |
           # stop the build if there are Python syntax errors or undefined names
           make ruff-check
-      - name: Run Tox
-        run: tox
+      - name: MyPy
+        run: mypy django_mail_viewer
+      - name: Run Tests
+        run: |
+          coverage run --source django_mail_viewer runtests.py
+          coverage report
diff --git a/Dockerfile b/Dockerfile
index d8f625b..7f8be6b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,6 @@
-FROM python:3.8-bookworm AS dev
+ARG PYTHON_VERSION=3.8
+ARG DEBIAN_DISTRO=bookworm
+FROM python:${PYTHON_VERSION}-${DEBIAN_DISTRO} AS dev
 # Dockerfile for running a test django installation
 LABEL maintainer="Justin Michalicek <jmichalicek@gmail.com>"
 ENV PYTHONUNBUFFERED 1
diff --git a/django_mail_viewer/__init__.py b/django_mail_viewer/__init__.py
index 04188a1..8a124bf 100644
--- a/django_mail_viewer/__init__.py
+++ b/django_mail_viewer/__init__.py
@@ -1 +1 @@
-__version__ = '2.2.0'
+__version__ = "2.2.0"
diff --git a/django_mail_viewer/backends/database/models.py b/django_mail_viewer/backends/database/models.py
index 49afe3a..dfaaeb1 100644
--- a/django_mail_viewer/backends/database/models.py
+++ b/django_mail_viewer/backends/database/models.py
@@ -1,7 +1,7 @@
 import email.message
 import email.utils
 import json
-from typing import TYPE_CHECKING, Any, Dict, List, Union
+from typing import Any, Dict, List, Union
 
 from django.db import models
 
@@ -12,7 +12,7 @@ class AbstractBaseEmailMessage(models.Model):
     storage for the Message FileField. Once Django 3.1+ only is supported then a callable may be used
     rendering this not really necessary.
 
-    To customize, subclass this and add a `FileField()` named `serialized_message_file` with the storage you would
+    To customize, subclass this and add a `FileField()` named `file_attachment` with the storage you would
     like to use.
     """
 
@@ -30,17 +30,11 @@ class AbstractBaseEmailMessage(models.Model):
     created_at = models.DateTimeField(auto_now_add=True)
     updated_at = models.DateTimeField(auto_now=True)
 
+    file_attachment: models.FileField
+
     class Meta:
         abstract = True
 
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-
-        # methods here expect the concrete subclasses to implement the file_attachment field
-        # should only be necessary until django 2.2 support is dropped... I hope
-        if TYPE_CHECKING and not hasattr(self, "file_attachment"):
-            self.file_attachment = models.FileField(blank=True, default="", upload_to="mailviewer_attachments")
-
     # I really only need/use get_filename(), get_content_type(), get_payload(), walk()
     # returns Any due to failobj
     def get(self, attr: str, failobj: Any = None) -> Any:
diff --git a/pyproject.toml b/pyproject.toml
index 82dcca0..6281801 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,9 +1,11 @@
 [tool.mypy]
 plugins = ["mypy_django_plugin.main"]
+ignore_missing_imports = true
 # for some reason this is not following the ignore of the settings file...
 exclude = [
   'migrations',
-  'test_project\/test_project\/settings\.py'
+  'test_project\/test_project\/settings\.py',
+  'docs',
 ]
 
 [tool.django-stubs]
diff --git a/requirements_test.txt b/requirements_test.txt
index 35d19b5..4bded55 100644
--- a/requirements_test.txt
+++ b/requirements_test.txt
@@ -4,8 +4,7 @@ flake8
 pytest
 tox
 tox-gh-actions
-django-stubs
-mypy
+django-stubs[compatible-mypy]
 typing-extensions
 black
 ruff
diff --git a/test_project/__init__.py b/test_project/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tox.ini b/tox.ini
deleted file mode 100644
index 0af8cc6..0000000
--- a/tox.ini
+++ /dev/null
@@ -1,40 +0,0 @@
-[tox]
-envlist =
-    {py38,py39,py310,311,312}-django-42
-    {py310,311,312}-django-50
-    {py310,311,312}-django-51
-    {py310,311,312}-django-52
-    stats
-
-[gh-actions]
-python =
-    3.8: py38
-    3.9: py39
-    3.10: py310
-    3.11: py311
-    3.11: py312
-
-[testenv]
-setenv =
-    PYTHONPATH = {toxinidir}:{toxinidir}/django_mail_viewer
-commands =
-  coverage run --source django_mail_viewer runtests.py
-  mypy django_mail_viewer
-
-deps =
-    django-32: Django>=3.2,<3.3
-    django-40: Django>=4.0,<4.1
-    django-41: Django>=4.1,<4.2
-    -r{toxinidir}/requirements_test.txt
-
-basepython =
-    py38: python3.8
-    py39: python3.9
-    py310: python3.10
-    py311: python3.11
-    py312: python3.12
-    stats: python3.9
-
-[testenv:stats]
-commands=
-    coverage report