diff --git a/.ambient-package-update/metadata.py b/.ambient-package-update/metadata.py
index 4e8d4c4..a0a390b 100644
--- a/.ambient-package-update/metadata.py
+++ b/.ambient-package-update/metadata.py
@@ -1,5 +1,10 @@
 from ambient_package_update.metadata.author import PackageAuthor
-from ambient_package_update.metadata.constants import DEV_DEPENDENCIES, LICENSE_GPL
+from ambient_package_update.metadata.constants import (
+    DEV_DEPENDENCIES,
+    LICENSE_GPL,
+    SUPPORTED_DJANGO_VERSIONS,
+    SUPPORTED_PYTHON_VERSIONS,
+)
 from ambient_package_update.metadata.package import PackageMetadata
 from ambient_package_update.metadata.readme import ReadmeContent
 from ambient_package_update.metadata.ruff_ignored_inspection import RuffIgnoredInspection
@@ -46,6 +51,8 @@
         'Django>=3.2',
         'html2text>=2020.1.16',
     ],
+    supported_django_versions=SUPPORTED_DJANGO_VERSIONS,
+    supported_python_versions=SUPPORTED_PYTHON_VERSIONS,
     optional_dependencies={
         'dev': [
             *DEV_DEPENDENCIES,
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 930c6d6..9c34bf3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,10 +8,10 @@ jobs:
   linting:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Set up Python 3.12
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.12"
 
@@ -21,13 +21,13 @@ jobs:
       - name: Run pre-commit hooks
         run: pre-commit run --all-files --hook-stage push
 
-  build:
+  tests:
     name: Python ${{ matrix.python-version }}, django ${{ matrix.django-version }}
     runs-on: ubuntu-22.04
     strategy:
       matrix:
-        python-version: [3.8, 3.9, '3.10', '3.11', '3.12']
-        django-version: [32, 41, 42]
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', ]
+        django-version: ['32', '41', '42', ]
 
         exclude:
           - python-version: '3.12'
@@ -38,9 +38,9 @@ jobs:
             django-version: 32
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: setup python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install tox
@@ -49,3 +49,40 @@ jobs:
         env:
           TOXENV: django${{ matrix.django-version }}
         run: tox
+      - name: Upload coverage data
+        uses: actions/upload-artifact@v3
+        with:
+          name: coverage-data
+          path: '.coverage*'
+
+  coverage:
+    name: Coverage
+    runs-on: ubuntu-22.04
+    needs: tests
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v4
+        with:
+          python-version: '3.12'
+
+      - name: Install dependencies
+        run: python -m pip install --upgrade coverage[toml]
+
+      - name: Download data
+        uses: actions/download-artifact@v3
+        with:
+          name: coverage-data
+
+      - name: Combine coverage and fail if it's <100%
+        run: |
+          # python -m coverage combine
+          python -m coverage html --skip-covered --skip-empty
+          python -m coverage report --fail-under=100
+
+      - name: Upload HTML report
+        if: ${{ failure() }}
+        uses: actions/upload-artifact@v3
+        with:
+          name: html-report
+          path: htmlcov
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0fd048d..1c3cffc 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,20 +3,20 @@
 
 repos:
   - repo: https://github.com/psf/black-pre-commit-mirror
-    rev: 23.9.1
+    rev: 23.10.0
     hooks:
       - id: black
         args: [ --check, --diff, --config, ./pyproject.toml ]
         stages: [ push ]
 
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: 'v0.0.292'
+    rev: 'v0.1.1'
     hooks:
       - id: ruff
-        args: [ --fix, --exit-non-zero-on-fix ]
+        args: [ --fix, --unsafe-fixes, --exit-non-zero-on-fix ]
 
   - repo: https://github.com/asottile/pyupgrade
-    rev: v3.14.0
+    rev: v3.15.0
     hooks:
       - id: pyupgrade
         args: [ --py38-plus ]
diff --git a/CHANGES.md b/CHANGES.md
index cad3c9b..0cacafe 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,9 @@
 # Changelog
 
+* *1.2.3** (2023-10-20)
+  * Linter updaters including code adjustments
+  * Updates from ambient updater
+
 * *1.2.2** (2023-10-04)
   * Dependency to ambient updater updated
 
diff --git a/README.md b/README.md
index f92fae0..a469bfb 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 [![PyPI release](https://img.shields.io/pypi/v/django-pony-express.svg)](https://pypi.org/project/django-pony-express/)
 [![Downloads](https://static.pepy.tech/badge/django-pony-express)](https://pepy.tech/project/django-pony-express)
+[![Coverage](https://img.shields.io/badge/Coverage-100%25-success)](https://github.com/ambient-innovation/django-pony-express/actions?workflow=CI)
 [![Linting](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)
 [![Coding Style](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/python/black)
 [![Documentation Status](https://readthedocs.org/projects/django-pony-express/badge/?version=latest)](https://django-pony-express.readthedocs.io/en/latest/?badge=latest)
@@ -80,6 +81,12 @@ Ingenious, right?
   pytest --ds settings tests
   ````
 
+- Check coverage
+  ````
+  coverage run -m pytest --ds settings tests
+  coverage report -m
+  ````
+
 ### Git hooks (via pre-commit)
 
 We use pre-push hooks to ensure that only linted code reaches our remote repository and pipelines aren't triggered in
diff --git a/django_pony_express/__init__.py b/django_pony_express/__init__.py
index 480109f..c91ce1c 100644
--- a/django_pony_express/__init__.py
+++ b/django_pony_express/__init__.py
@@ -1,3 +1,3 @@
 """Class-based emails including a test suite for Django"""
 
-__version__ = '1.2.2'
+__version__ = '1.2.3'
diff --git a/django_pony_express/services/base.py b/django_pony_express/services/base.py
index 6c7d548..5480c50 100644
--- a/django_pony_express/services/base.py
+++ b/django_pony_express/services/base.py
@@ -188,8 +188,13 @@ def get_translation(self) -> Union[str, None]:
         """
         Tries to fetch the current translation from the django settings.
         """
+        language_str_length = 2
         try:
-            return settings.LANGUAGE_CODE[:2] if settings.LANGUAGE_CODE and len(settings.LANGUAGE_CODE) >= 2 else None
+            return (
+                settings.LANGUAGE_CODE[:2]
+                if settings.LANGUAGE_CODE and len(settings.LANGUAGE_CODE) >= language_str_length
+                else None
+            )
         except TypeError:
             return None
 
diff --git a/django_pony_express/services/tests.py b/django_pony_express/services/tests.py
index 641c5ba..a559e7e 100644
--- a/django_pony_express/services/tests.py
+++ b/django_pony_express/services/tests.py
@@ -78,9 +78,7 @@ def all(self):
         self.reload()
 
         # Load data to matching list
-        match_list = []
-        for email in self._outbox:
-            match_list.append(email)
+        match_list = list(self._outbox)
 
         return EmailTestServiceQuerySet(matching_list=match_list)
 
diff --git a/pyproject.toml b/pyproject.toml
index 9436bf7..f1609bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,14 +41,14 @@ dev = [
    'freezegun~=1.2',
    'pytest-django~=4.5',
    'pytest-mock~=3.10',
-   'pre-commit~=3.2',
-   'black~=23.3',
-   'Django~=3.2',
+   'coverage~=7.3',
+   'pre-commit~=3.5',
+   'black~=23.10',
    'sphinx==4.2.0',
    'sphinx-rtd-theme==1.0.0',
    'm2r2==0.3.1',
    'mistune<2.0.0',
-   'ambient-package-update~=23.10.1',
+   'ambient-package-update~=23.10.2',
 ]
 
 [tool.flit.module]
@@ -88,8 +88,9 @@ select = [
     "PIE",     # Bunch of useful rules
     # "SIM",     # Simplifies your code
     "INT",     # Validates your gettext translation strings
+    "PERF",    # PerfLint
     "PGH",     # No all-purpose "# noqa" and eval validation
-    # "UP",      # PyUpgrade
+    "PL",      # PyLint
 ]
 ignore = [
     'N999', # Project name contains underscore, not fixable
@@ -116,8 +117,9 @@ fixable = [
     "PIE",     # Bunch of useful rules
     # "SIM",     # Simplifies your code
     "INT",     # Validates your gettext translation strings
+    "PERF",    # PerfLint
     "PGH",     # No all-purpose "# noqa" and eval validation
-    # "UP",      # PyUpgrade
+    "PL",      # PyLint
 ]
 unfixable = []
 
@@ -163,12 +165,12 @@ isolated_build = True
 [testenv]
 # Django deprecation overview: https://www.djangoproject.com/download/
 deps =
-    django32: Django>=3.2,<3.3
-    django41: Django>=4.1,<4.2
-    django42: Django>=4.2,<4.3
+    django32: Django==3.2.*
+    django41: Django==4.1.*
+    django42: Django==4.2.*
 extras = dev,
 commands =
-    pytest --ds settings tests
+    coverage run -m pytest --ds settings tests
 
 [gh-actions]
 python =
diff --git a/scripts/unix/install_requirements.sh b/scripts/unix/install_requirements.sh
new file mode 100644
index 0000000..36adaba
--- /dev/null
+++ b/scripts/unix/install_requirements.sh
@@ -0,0 +1,3 @@
+pip install -U pip-tools
+pip-compile --extra dev, -o requirements.txt pyproject.toml --resolver=backtracking
+pip-sync
diff --git a/scripts/windows/install_requirements.ps1 b/scripts/windows/install_requirements.ps1
new file mode 100644
index 0000000..36adaba
--- /dev/null
+++ b/scripts/windows/install_requirements.ps1
@@ -0,0 +1,3 @@
+pip install -U pip-tools
+pip-compile --extra dev, -o requirements.txt pyproject.toml --resolver=backtracking
+pip-sync
diff --git a/setup.cfg b/setup.cfg
index ef803ed..5f27401 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,3 +1,18 @@
 [metadata]
 description-file = README.md
 license-file = LICENSE.md
+
+[coverage:run]
+branch = True
+parallel = True
+source =
+    django_pony_express
+    tests
+
+[coverage:paths]
+source =
+    django_pony_express
+    .tox/**/site-packages
+
+[coverage:report]
+show_missing = True