diff --git a/.github/workflows/linter.yaml b/.github/workflows/linter.yaml
index 2d1ecc80..fc5185e8 100644
--- a/.github/workflows/linter.yaml
+++ b/.github/workflows/linter.yaml
@@ -36,7 +36,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        django-version: [django320]
+        django-version: [django420]
     steps:
       - run: |
           sudo apt update
@@ -44,9 +44,9 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: 3.9
+          python-version: 3.11
       - name: Install tox
         run: |
           python3 -m pip install --upgrade pip
-          python3 -m pip install 'tox<4.0'
+          python3 -m pip install tox
       - run: tox -e mypy-${{ matrix.django-version }}
diff --git a/.github/workflows/unittests.yaml b/.github/workflows/unittests.yaml
index b32b8890..d430abf6 100644
--- a/.github/workflows/unittests.yaml
+++ b/.github/workflows/unittests.yaml
@@ -17,18 +17,9 @@ jobs:
       max-parallel: 7
       matrix:
         python-version: [3.9, '3.10', '3.11']
-        django-version: [django320, django420]
+        django-version: [django420]
         db: [sqlite]
         include:
-          - python-version: '3.11'
-            django-version: django320
-            db: mysql
-          - python-version: '3.11'
-            django-version: django320
-            db: mariadb
-          - python-version: '3.11'
-            django-version: django320
-            db: postgres
           - python-version: '3.11'
             django-version: django420
             db: mysql
diff --git a/src/tcms/core/ajax.py b/src/tcms/core/ajax.py
index 5cd88817..b880dfbe 100644
--- a/src/tcms/core/ajax.py
+++ b/src/tcms/core/ajax.py
@@ -328,9 +328,7 @@ def _record_log_actions(log_actions_info: list[LogActionInfo]) -> None:
                         params["who"],
                     )
 
-    def _simple_update(
-        self, models: Union[QuerySet, list[TCMSActionModel]], new_value: Any
-    ) -> None:
+    def _simple_update(self, models, new_value: Any) -> None:
         """A simple update method for most cases to update property of a set of cases
 
         In the most of the cases, the property update requires two steps, one is to update the
@@ -355,19 +353,13 @@ def _simple_update(
             if original_value == str(new_value):
                 continue
 
-            log_actions_info.append(
-                (
-                    model,
-                    [
-                        {
-                            "who": self.request.user,
-                            "field": self.target_field,
-                            "original_value": original_value,
-                            "new_value": str(new_value),
-                        }
-                    ],
-                )
-            )
+            params = {
+                "who": self.request.user,
+                "field": self.target_field,
+                "original_value": original_value,
+                "new_value": str(new_value),
+            }
+            log_actions_info.append((model, [params]))
 
             setattr(model, self.target_field, new_value)
             changed.append(model)
@@ -451,7 +443,7 @@ def __init__(self, *args, **kwargs):
         f.queryset = TestCaseRun.objects.select_related("case", "assignee").only(
             "case", "assignee__username"
         )
-        f: forms.ModelChoiceField = self.fields["new_value"]
+        f = self.fields["new_value"]
         new_assignee_pk = self.data.get("new_value")
         f.error_messages["invalid_choice"] = f"No user with id {new_assignee_pk} exists."
 
@@ -488,7 +480,7 @@ def __init__(self, *args, **kwargs):
         f.queryset = TestCaseRun.objects.select_related("case_run_status", "tested_by").only(
             "close_date", "tested_by__username", "case_run_status__name"
         )
-        f: forms.ModelChoiceField = self.fields["new_value"]
+        f = self.fields["new_value"]
         new_status = self.data.get("new_value")
         f.error_messages[
             "invalid_choice"
@@ -517,15 +509,14 @@ def _update_case_run_status(self):
         if not f.is_valid():
             return JsonResponseBadRequest({"message": form_error_messages_to_list(f)})
 
-        request_user: User = self.request.user
+        request_user = self.request.user
         new_status = f.cleaned_data["new_value"]
         update_time = datetime.datetime.now()
 
         log_actions_info = []
-        changed: list[TestCaseRun] = []
+        changed = []
         tested_by_changed = False
 
-        case_run: TestCaseRun
         for case_run in f.cleaned_data["case_run"]:
             if case_run.case_run_status == new_status:
                 continue
@@ -618,7 +609,7 @@ def __init__(self, *args, **kwargs):
         f.queryset = TestCase.objects.select_related("default_tester").only(
             "default_tester__username"
         )
-        f: forms.ModelChoiceField = self.fields["new_value"]
+        f = self.fields["new_value"]
         f.error_messages["invalid_choice"] = (
             f"{self.data['new_value']} cannot be set as a default tester, "
             f"since this user does not exist."
@@ -654,7 +645,7 @@ def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         f = self.fields["case"]
         f.queryset = TestCase.objects.select_related("reviewer").only("reviewer__username")
-        f: forms.ModelChoiceField = self.fields["new_value"]
+        f = self.fields["new_value"]
         f.error_messages["invalid_choice"] = f"Reviewer {self.data['new_value']} is not found"
 
 
@@ -680,7 +671,7 @@ class PatchTestCaseSortKeyForm(PatchTestCaseBaseForm):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.fields["case"].queryset = TestCase.objects.only("pk")
-        f: forms.ModelChoiceField = self.fields["plan"]
+        f = self.fields["plan"]
         f.error_messages["invalid_choice"] = f"No plan with id {self.data['plan']} exists."
 
 
diff --git a/src/tcms/core/files.py b/src/tcms/core/files.py
index d13ac380..648c1836 100644
--- a/src/tcms/core/files.py
+++ b/src/tcms/core/files.py
@@ -64,7 +64,7 @@ def post(self, request):
         if not upload_file:
             return HttpResponseRedirect(redirect_url)
 
-        upload_file: UploadedFile = request.FILES["upload_file"]
+        upload_file = request.FILES["upload_file"]
 
         if upload_file.size > settings.MAX_UPLOAD_SIZE:
             return prompt.alert(
diff --git a/src/tcms/core/views/prompt.py b/src/tcms/core/views/prompt.py
index 3d1b992e..d3bdb166 100644
--- a/src/tcms/core/views/prompt.py
+++ b/src/tcms/core/views/prompt.py
@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 # FIXME: Use exception to replace the feature
 
+from typing import Optional
+
 from django.http import HttpRequest
 from django.shortcuts import render
 
@@ -8,7 +10,7 @@
 PROMPT_INFO = "info"
 
 
-def alert(request: HttpRequest, content: str, next_: str = None):
+def alert(request: HttpRequest, content: str, next_: Optional[str] = None):
     return render(
         request,
         "prompt.html",
@@ -16,7 +18,7 @@ def alert(request: HttpRequest, content: str, next_: str = None):
     )
 
 
-def info(request: HttpRequest, content: str, next_: str = None):
+def info(request: HttpRequest, content: str, next_: Optional[str] = None):
     return render(
         request,
         "prompt.html",
diff --git a/src/tcms/management/models.py b/src/tcms/management/models.py
index 3f655b9b..7dda47b3 100644
--- a/src/tcms/management/models.py
+++ b/src/tcms/management/models.py
@@ -251,8 +251,7 @@ def to_xmlrpc(cls, query=None):
         return s.serialize_queryset()
 
     @classmethod
-    def search(cls, query):
-        val: Any
+    def search(cls, query: dict[str, Any]):
         criteria: dict[str, Any] = {}
 
         if val := query.get("build_id"):
@@ -536,7 +535,7 @@ def get_active(cls):
 
 
 # FIXME: plugins_support is no longer available, this is dead code.
-if register_model:
+if register_model:  # type: ignore
     register_model(Classification)
     register_model(Product)
     register_model(Priority)
diff --git a/src/tcms/testcases/models.py b/src/tcms/testcases/models.py
index 16166a42..492697b0 100644
--- a/src/tcms/testcases/models.py
+++ b/src/tcms/testcases/models.py
@@ -2,7 +2,7 @@
 
 import logging
 from datetime import datetime
-from typing import Any, Optional, Union
+from typing import Any, Dict, Optional, Union
 
 from django.conf import settings
 from django.contrib.contenttypes.fields import GenericRelation
@@ -235,7 +235,7 @@ def update(cls, case_ids, values):
         return tcs
 
     @classmethod
-    def search(cls, query, plan=None):
+    def search(cls, query: Dict[str, Any], plan: Optional[int] = None) -> QuerySet["TestCase"]:
         """List the cases with request"""
         from django.db.models import Q
 
@@ -1052,7 +1052,7 @@ def _listen():
 if settings.LISTENING_MODEL_SIGNAL:
     _listen()
 
-if register_model:
+if register_model:  # type: ignore
     register_model(TestCase)
     register_model(TestCaseText)
     register_model(TestCasePlan)
diff --git a/src/tcms/testcases/views.py b/src/tcms/testcases/views.py
index e63ed823..6ce30783 100644
--- a/src/tcms/testcases/views.py
+++ b/src/tcms/testcases/views.py
@@ -763,7 +763,7 @@ def get_context_data(self, **kwargs):
         this_cls = TestCaseCaseRunDetailPanelView
         data = super(this_cls, self).get_context_data(**kwargs)
 
-        case: TestCase = get_object_or_404(TestCase.objects.only("pk"), pk=self.case_id)
+        case = get_object_or_404(TestCase.objects.only("pk"), pk=self.case_id)
         case_run = get_object_or_404(TestCaseRun, pk=self.case_run_id, case=case)
 
         # Data of TestCase
@@ -1250,7 +1250,6 @@ def clone(request, template_name="case/clone.html"):
             src_plan = plan_from_request_or_none(request)
             dest_case = None
 
-            src_cases: TestCase
             for src_case in src_cases:
                 author = None if keep_orig_author else request.user
                 default_tester = None if keep_orig_default_tester else request.user
diff --git a/src/tcms/testplans/models.py b/src/tcms/testplans/models.py
index 55531776..69268096 100644
--- a/src/tcms/testplans/models.py
+++ b/src/tcms/testplans/models.py
@@ -80,7 +80,7 @@ class TestPlan(TCMSActionModel):
     )
     env_group = models.ManyToManyField(
         "management.TCMSEnvGroup", related_name="plans", through="TCMSEnvPlanMap"
-    )
+    )  # type: ignore
     tag = models.ManyToManyField("management.TestTag", through="testplans.TestPlanTag")
 
     class Meta:
@@ -634,7 +634,7 @@ def set_email_settings_to_new_plan(sender, **kwargs):
         TestPlanEmailSettings.objects.create(plan=kwargs["instance"])
 
 
-if register_model:
+if register_model:  # type: ignore
     register_model(TestPlan)
     register_model(TestPlanText)
     register_model(TestPlanType)
diff --git a/src/tcms/testplans/views.py b/src/tcms/testplans/views.py
index 158ca848..37d915b7 100644
--- a/src/tcms/testplans/views.py
+++ b/src/tcms/testplans/views.py
@@ -994,7 +994,7 @@ def handle_no_permission(self):
         )
 
     def patch(self, request, *args, **kwargs):
-        plan: TestPlan = TestPlan.objects.filter(pk=self.kwargs["plan_id"]).only("pk").first()
+        plan = TestPlan.objects.filter(pk=self.kwargs["plan_id"]).only("pk").first()
         if plan is None:
             return JsonResponseNotFound(
                 {
@@ -1004,7 +1004,7 @@ def patch(self, request, *args, **kwargs):
             )
 
         data = json.loads(request.body)
-        user_input: Optional[str] = data.get("parent")
+        user_input = data.get("parent")
         if user_input is None:
             return JsonResponseBadRequest({"message": "Missing parent plan id."})
         if not isinstance(user_input, int):
@@ -1049,10 +1049,10 @@ class SetPlanActiveView(PermissionRequiredMixin, View):
 
     def patch(self, request, *args, **kwargs):
         plan_id = self.kwargs["plan_id"]
-        plan: TestPlan = TestPlan.objects.filter(pk=plan_id).only("is_active").first()
+        plan = TestPlan.objects.filter(pk=plan_id).only("is_active").first()
         if not plan:
             return JsonResponseNotFound({"message": f"Plan id {plan_id} does not exist."})
-        original_value: str = str(plan.is_active)
+        original_value = str(plan.is_active)
         plan.is_active = self.enable
         plan.save(update_fields=["is_active"])
         plan.log_action(
diff --git a/src/tcms/testruns/helpers/serializer.py b/src/tcms/testruns/helpers/serializer.py
index 39903dbc..6eb88368 100644
--- a/src/tcms/testruns/helpers/serializer.py
+++ b/src/tcms/testruns/helpers/serializer.py
@@ -5,7 +5,6 @@
 
 import csv
 
-from django.template import Template
 from django.template.loader import get_template
 
 # TODO: rewrite export module to export TestCaseRuns, TestPlans and other
@@ -84,5 +83,5 @@ def write_to_xml(self, output):
         .. versionchanged:: 4.2
            Element ``bugs`` is renamed to ``issues``.
         """
-        xml_template: Template = get_template("run/export-to.xml")
+        xml_template = get_template("run/export-to.xml")
         output.write(xml_template.render({"case_runs": self.tcrs}))
diff --git a/src/tcms/testruns/models.py b/src/tcms/testruns/models.py
index 74850ff5..dfd69e9f 100644
--- a/src/tcms/testruns/models.py
+++ b/src/tcms/testruns/models.py
@@ -229,7 +229,7 @@ def add_cc(self, user):
     def add_env_value(self, env_value: TCMSEnvValue):
         return TCMSEnvRunValueMap.objects.get_or_create(run=self, value=env_value)
 
-    def remove_tag(self, tag):
+    def remove_tag(self, tag: TestTag) -> None:
         cursor = connection.writer_cursor
         cursor.execute(
             "DELETE from test_run_tags WHERE run_id = %s AND tag_id = %s",
@@ -617,7 +617,7 @@ def _run_listen():
 if settings.LISTENING_MODEL_SIGNAL:
     _run_listen()
 
-if register_model:
+if register_model:  # type: ignore
     register_model(TestRun)
     register_model(TestCaseRun)
     register_model(TestRunTag)
diff --git a/src/tcms/testruns/views.py b/src/tcms/testruns/views.py
index 9b90f559..50389a4e 100644
--- a/src/tcms/testruns/views.py
+++ b/src/tcms/testruns/views.py
@@ -610,7 +610,7 @@ class RunStatisticsView(TemplateView):
     def get_context_data(self, **kwargs):
         data = super().get_context_data()
         run_id = self.kwargs["run_id"]
-        run: TestRun = get_object_or_404(TestRun.objects.only("pk"), pk=run_id)
+        run = get_object_or_404(TestRun.objects.only("pk"), pk=run_id)
         data.update(
             {
                 "test_run": run,
@@ -628,7 +628,7 @@ def get(request, run_id, template_name="run/get.html"):
     SUB_MODULE_NAME = "runs"
 
     # Get the test run
-    tr: TestRun = get_object_or_404(TestRun.objects.select_related(), pk=run_id)
+    tr = get_object_or_404(TestRun.objects.select_related(), pk=run_id)
 
     # Get the test case runs belong to the run
     # 2. get test run's all case runs
@@ -695,7 +695,7 @@ def edit(request, run_id, template_name="run/edit.html"):
     SUB_MODULE_NAME = "runs"
 
     try:
-        tr: TestRun = TestRun.objects.select_related().get(run_id=run_id)
+        tr = TestRun.objects.select_related().get(run_id=run_id)
     except ObjectDoesNotExist:
         raise Http404
 
@@ -821,7 +821,6 @@ def get_context_data(self, **kwargs):
         automated_count = 0
         manual_automated_count = 0
 
-        case_run: TestCaseRun
         for case_run in case_runs:
             case_run.display_issues = issues_by_case_run.get(case_run.pk, ())
             user_comments = comments.get(case_run.pk, [])
diff --git a/src/tcms/xmlrpc/api/testrun.py b/src/tcms/xmlrpc/api/testrun.py
index 0aeb4ca1..02681044 100644
--- a/src/tcms/xmlrpc/api/testrun.py
+++ b/src/tcms/xmlrpc/api/testrun.py
@@ -132,11 +132,10 @@ def add_tag(request, run_ids, tags):
         TestPlan.add_tag('1, 2', 'foo, bar')
     """
     trs = TestRun.objects.filter(pk__in=pre_process_ids(value=run_ids))
-    tags: list[str] = TestTag.string_to_list(tags)
+    tags = TestTag.string_to_list(tags)
 
     for tag in tags:
         t, _ = TestTag.objects.get_or_create(name=tag)
-        tr: TestRun
         for tr in trs.iterator():
             tr.add_tag(tag=t)
 
@@ -533,7 +532,6 @@ def remove_tag(request, run_ids, tags):
     trs = TestRun.objects.filter(run_id__in=pre_process_ids(value=run_ids))
     tgs = TestTag.objects.filter(name__in=TestTag.string_to_list(tags))
 
-    tr: TestRun
     for tr in trs.iterator():
         for tg in tgs.iterator():
             tr.remove_tag(tag=tg)
diff --git a/tests/__init__.py b/tests/__init__.py
index bc70ad9a..8a661c25 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -5,6 +5,7 @@
 import re
 from functools import partial
 from http import HTTPStatus
+from typing import ClassVar
 from urllib.parse import parse_qs, urlparse
 
 from django import test
@@ -230,6 +231,9 @@ def get_max_plan_id(self):
 class BasePlanCase(AuthMixin, HelperAssertions, NitrateTestCase):
     """Base test case by providing essential Plan and Case objects used in tests"""
 
+    case_1: ClassVar
+    case_3: ClassVar
+
     @classmethod
     def setUpTestData(cls):
         super().setUpTestData()
diff --git a/tests/conftest.py b/tests/conftest.py
index 0f6a353b..00237267 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -15,7 +15,7 @@
 
 @pytest.fixture
 def tester(django_user_model):
-    user: User = django_user_model.objects.create(username="tester", email="tester@example.com")
+    user = django_user_model.objects.create(username="tester", email="tester@example.com")
     user.set_password(TESTER_PASSWORD)
     user.save()
     return user
diff --git a/tests/core/test_ajax.py b/tests/core/test_ajax.py
index f3cbb8a4..a36c1ec6 100644
--- a/tests/core/test_ajax.py
+++ b/tests/core/test_ajax.py
@@ -111,8 +111,6 @@ def test_change_assignee(self):
         mail.outbox = []
         update_targets = [self.case_run_1, self.case_run_3]
 
-        case_run: TestCaseRun
-
         resp = self.client.patch(
             self.url,
             data={
@@ -196,7 +194,7 @@ def test_ensure_mail_notify_is_sent(self):
         case = TestCase.objects.get(pk=self.case_2.pk)
         self.assertEqual(self.reviewer.username, case.reviewer.username)
 
-        out_mail: EmailMessage = mail.outbox[0]
+        out_mail = mail.outbox[0]
 
         self.assertEqual("You have been the reviewer of cases", out_mail.subject)
         self.assertListEqual([self.reviewer.email], out_mail.recipients())
@@ -248,7 +246,6 @@ def test_change_status(self):
 
         self.assertEqual(200, resp.status_code)
 
-        case_run: TestCaseRun
         for case_run in [self.case_run_1, self.case_run_3]:
             self.assertEqual(
                 self.running_status, TestCaseRun.objects.get(pk=case_run.pk).case_run_status
@@ -379,10 +376,9 @@ def test_new_sort_key_is_not_in_range(self):
 
     def test_update_sort_key(self):
         new_sort_key = 2
-        update_targets: list[TestCaseRun] = [self.case_run_2, self.case_run_4]
+        update_targets = [self.case_run_2, self.case_run_4]
 
-        case_run: TestCaseRun
-        update_targets_pks: list[int] = [case_run.pk for case_run in update_targets]
+        update_targets_pks = [case_run.pk for case_run in update_targets]
 
         resp = self.client.patch(
             self.url,
@@ -408,7 +404,7 @@ def test_update_sort_key(self):
             )
 
         # Other case runs' sortkey should not be changed.
-        sort_keys: list[int] = TestCaseRun.objects.exclude(pk__in=update_targets_pks).values_list(
+        sort_keys = TestCaseRun.objects.exclude(pk__in=update_targets_pks).values_list(
             "sortkey", flat=True
         )
         for sort_key in sort_keys:
@@ -451,7 +447,6 @@ def test_set_default_tester(self):
 
         self.assertJsonResponse(resp, {})
 
-        case: TestCase
         for case in [self.case_1, self.case_2]:
             self.assertEqual(self.user_1, TestCase.objects.get(pk=case.pk).default_tester)
             self.assertTrue(
@@ -487,7 +482,6 @@ def test_given_username_does_not_exist(self):
             status_code=HTTPStatus.BAD_REQUEST,
         )
 
-        case: TestCase
         for case in [self.case_1, self.case_2]:
             self.assertEqual(case.default_tester, TestCase.objects.get(pk=case.pk).default_tester)
 
@@ -518,7 +512,6 @@ def test_change_priority(self):
         self.assertEqual(p4, TestCase.objects.get(pk=self.case_1.pk).priority)
         self.assertEqual(p4, TestCase.objects.get(pk=self.case_3.pk).priority)
 
-        case: TestCase
         for case in [self.case_1, self.case_3]:
             self.assertTrue(
                 TCMSLogModel.objects.filter(
@@ -565,7 +558,6 @@ def test_change_reviewer(self):
         resp = self.client.patch(self.url, data=data, content_type="application/json")
         self.assert200(resp)
 
-        case: TestCase
         for case in [self.case_1, self.case_3]:
             self.assertEqual(self.reviewer, TestCase.objects.get(pk=case.pk).reviewer)
             self.assertTrue(
@@ -612,7 +604,6 @@ def test_change_status(self):
         resp = self.client.patch(self.url, data=data, content_type="application/json")
         self.assertJsonResponse(resp, {})
 
-        case: TestCase
         for case in [self.case_1, self.case_3]:
             self.assertEqual(
                 self.case_status_proposed, TestCase.objects.get(pk=case.pk).case_status
diff --git a/tests/core/test_files.py b/tests/core/test_files.py
index d4a492cc..8b9acc78 100644
--- a/tests/core/test_files.py
+++ b/tests/core/test_files.py
@@ -44,7 +44,7 @@ def setUp(self):
         klass_name = self.__class__.__name__
         self.working_dir = tempfile.mkdtemp(prefix=klass_name)
 
-        file_content: bytes = b"abc" * 100
+        file_content = b"abc" * 100
 
         fd, self.upload_filename = tempfile.mkstemp(
             suffix=f"{klass_name}-upload-file.txt", dir=self.working_dir
diff --git a/tests/core/test_views.py b/tests/core/test_views.py
index 124b96ca..4773f436 100644
--- a/tests/core/test_views.py
+++ b/tests/core/test_views.py
@@ -153,7 +153,7 @@ class TestIndexView(test.TestCase):
     @classmethod
     def setUpTestData(cls):
         cls.password = "password"
-        cls.user: User = User.objects.create(username="tester", email="tester@localhost")
+        cls.user = User.objects.create(username="tester", email="tester@localhost")
         cls.user.set_password(cls.password)
         cls.user.save()
 
diff --git a/tests/testplans/test_models.py b/tests/testplans/test_models.py
index a60e93f5..e8777910 100644
--- a/tests/testplans/test_models.py
+++ b/tests/testplans/test_models.py
@@ -198,7 +198,7 @@ def test_collect_recipients(self):
             es.auto_to_case_default_tester = bool(auto_to_case_default_tester)
             es.save()
 
-            plan: TestPlan = TestPlan.objects.get(pk=self.plan.pk)
+            plan = TestPlan.objects.get(pk=self.plan.pk)
 
             # Since this test contains the case of plan.owner is None,
             # recover the plan's owner here.
@@ -255,7 +255,7 @@ def setUpTestData(cls):
 
     def test_get_ancestor_ids(self):
         expected = [self.plan.pk, self.plan_2.pk, self.plan_3.pk]
-        plan: TestPlan = TestPlan.objects.get(pk=self.plan_4.pk)
+        plan = TestPlan.objects.get(pk=self.plan_4.pk)
         self.assertListEqual(expected, sorted(plan.get_ancestor_ids()))
 
     def test_get_ancestors(self):
@@ -275,7 +275,7 @@ def test_get_ancestors(self):
 
     def test_get_descendant_ids(self):
         expected = [self.plan_4.pk, self.plan_5.pk, self.plan_6.pk, self.plan_7.pk]
-        plan: TestPlan = TestPlan.objects.get(pk=self.plan_3.pk)
+        plan = TestPlan.objects.get(pk=self.plan_3.pk)
         self.assertListEqual(expected, sorted(plan.get_descendant_ids()))
 
     def test_get_descendants(self):
@@ -308,7 +308,7 @@ def test_get_direct_descendants(self):
         ]
 
         for parent_plan, expected in test_data:
-            plan: TestPlan = TestPlan.objects.get(pk=parent_plan)
+            plan = TestPlan.objects.get(pk=parent_plan)
             self.assertListEqual(expected, sorted(plan.get_descendant_ids(True)))
 
 
@@ -678,7 +678,7 @@ def test_plan_add_env_group(group_name, tester, base_data):
     else:
         env_group = TCMSEnvGroup.objects.create(name=group_name, manager=tester)
         plan.add_env_group(env_group)
-        rels: list[TCMSEnvPlanMap] = list(TCMSEnvPlanMap.objects.all())
+        rels = list(TCMSEnvPlanMap.objects.all())
         assert 1 == len(rels)
         assert env_group == rels[0].group
 
diff --git a/tests/testplans/test_views.py b/tests/testplans/test_views.py
index 000a40cf..fd6974e1 100644
--- a/tests/testplans/test_views.py
+++ b/tests/testplans/test_views.py
@@ -7,7 +7,7 @@
 import xml.etree.ElementTree as et
 from http import HTTPStatus
 from textwrap import dedent
-from typing import Optional, Union
+from typing import List, Optional, Tuple, Union
 from unittest.mock import Mock
 
 import pytest
@@ -1136,14 +1136,11 @@ def test_parent_is_a_descendant_already(self):
         )
 
     def test_change_parent(self):
-        targets = (
+        targets = [
             (self.plan_5, str(self.plan_5.parent.pk)),
             (self.plan_9, "None"),
-        )
-        new_parent: TestPlan = self.plan_3
-
-        target_plan: TestPlan
-        expected_original_value: str
+        ]
+        new_parent = self.plan_3
 
         for target_plan, expected_original_value in targets:
             resp = self.client.patch(
diff --git a/tests/testruns/test_views.py b/tests/testruns/test_views.py
index 67440818..00830f3a 100644
--- a/tests/testruns/test_views.py
+++ b/tests/testruns/test_views.py
@@ -1276,11 +1276,11 @@ def test_update_single_case_run(self):
         )
 
     def test_update_multiple_case_runs(self):
-        case_runs: list[int] = [self.case_run_1.pk, self.case_run_2.pk]
+        case_runs = [self.case_run_1.pk, self.case_run_2.pk]
         response = self.client.post(self.update_url, {"case_run": case_runs})
 
         for pk in case_runs:
-            case_run: TestCaseRun = TestCaseRun.objects.get(pk=pk)
+            case_run = TestCaseRun.objects.get(pk=pk)
             self.assertEqual(
                 case_run.case.latest_text_version(),
                 case_run.latest_text().case_text_version,
@@ -1338,8 +1338,8 @@ def test_edit_run(self):
         self.assertRedirects(response, reverse("run-get", args=[run.pk]))
 
     def test_auto_update_run_status_when_all_case_runs_complete(self):
-        case_run: QuerySet = self.test_run.case_run
-        case_run.update(case_run_status=TestCaseRunStatus.objects.get(name="PASSED"))
+        status_passed = TestCaseRunStatus.objects.get(name="PASSED")
+        self.test_run.case_run.update(case_run_status=status_passed)
 
         post_data = {
             "summary": "New run summary",
@@ -1360,7 +1360,7 @@ def test_auto_update_run_status_when_all_case_runs_complete(self):
         assert test_run.stop_date is not None
 
     def test_auto_update_run_status_when_partial_case_runs_complete(self):
-        case_runs: QuerySet[TestCaseRun] = self.test_run.case_run.all()
+        case_runs = self.test_run.case_run.all()
         case_runs[0].case_run_status = TestCaseRunStatus.objects.get(name="PASSED")
         case_runs[1].case_run_status = TestCaseRunStatus.objects.get(name="ERROR")
         case_runs[2].case_run_status = TestCaseRunStatus.objects.get(name="IDLE")
diff --git a/tests/xmlrpc/test_testrun.py b/tests/xmlrpc/test_testrun.py
index 4ce624d4..6b94da9b 100644
--- a/tests/xmlrpc/test_testrun.py
+++ b/tests/xmlrpc/test_testrun.py
@@ -18,6 +18,7 @@
 from tcms.xmlrpc.utils import pre_process_ids
 from tests import factories as f
 from tests import user_should_have_perm
+from tests.conftest import BaseDataContext
 from tests.xmlrpc.utils import XmlrpcAPIBaseTest, make_http_request
 
 
@@ -441,7 +442,7 @@ def test_get_tags(run_id: int, expected, tester, base_data):
         [2, [1, 2]],
     ],
 )
-def test_get_test_case_runs(run_id, expected, tester, base_data):
+def test_get_test_case_runs(run_id, expected, tester, base_data: BaseDataContext):
     plan = base_data.create_plan(pk=1, name="plan 1")
     case_1 = base_data.create_case(pk=1, summary="case 1")
     case_2 = base_data.create_case(pk=2, summary="case 2")
@@ -450,7 +451,7 @@ def test_get_test_case_runs(run_id, expected, tester, base_data):
     plan.add_case(case_2)
 
     base_data.create_test_run(pk=1, plan=plan)
-    run_2: TestRun = base_data.create_test_run(pk=2, plan=plan)
+    run_2 = base_data.create_test_run(pk=2, plan=plan)
     TestCaseRun.objects.create(
         pk=1,
         run=run_2,
diff --git a/tests/xmlrpc/test_user.py b/tests/xmlrpc/test_user.py
index d871e5c7..3953565b 100644
--- a/tests/xmlrpc/test_user.py
+++ b/tests/xmlrpc/test_user.py
@@ -172,7 +172,7 @@ def setUp(self) -> None:
     def test_update_myself(self):
         request = make_http_request(user=self.user)
         data = XUser.update(request, self.user_new_attrs, request.user.pk)
-        user: User = User.objects.get(pk=request.user.pk)
+        user = User.objects.get(pk=request.user.pk)
         self.assertEqual(data["first_name"], user.first_name)
         self.assertEqual(data["last_name"], user.last_name)
         self.assertEqual(data["email"], user.email)
@@ -180,7 +180,7 @@ def test_update_myself(self):
     def test_update_myself_without_passing_my_id(self):
         request = make_http_request(user=self.user)
         data = XUser.update(request, self.user_new_attrs)
-        user: User = User.objects.get(pk=request.user.pk)
+        user = User.objects.get(pk=request.user.pk)
         self.assertEqual(data["first_name"], user.first_name)
         self.assertEqual(data["last_name"], user.last_name)
         self.assertEqual(data["email"], user.email)
@@ -193,7 +193,7 @@ def test_cannot_update_other_user_without_permission(self):
     def test_update_other_with_proper_permission(self):
         request = make_http_request(user=self.user_with_perm)
         data = XUser.update(request, self.user_new_attrs, self.user.pk)
-        user: User = User.objects.get(pk=self.user.pk)
+        user = User.objects.get(pk=self.user.pk)
         self.assertEqual(data["first_name"], user.first_name)
         self.assertEqual(data["last_name"], user.last_name)
         self.assertEqual(data["email"], user.email)
diff --git a/tox.ini b/tox.ini
index 31e45e45..2ec87fed 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 envlist =
-    {py39,py310,py311}-django{320,420}-sqlite
-    py311-django{320,420}-{mysql,mariadb,postgres}
+    {py39,py310,py311}-django{420}-sqlite
+    py311-django{420}-{mysql,mariadb,postgres}
     flake8
     docs
     ; This is not that jslint :)
@@ -11,12 +11,11 @@ envlist =
     doc8
     isort
     bandit
-    mypy-django{320}
+    mypy-django{420}
 
 [testenv]
 passenv = *
 deps =
-    django320: Django>=3.2,<3.3
     django420: Django>=4.2,<4.3
 usedevelop = True
 extras =
@@ -42,7 +41,7 @@ environment =
     MYSQL_ROOT_PASSWORD=pass
     MYSQL_DATABASE=nitrate
 
-[testenv:{py39,py310}-django{320}-mysql]
+[testenv:{py39,py310}-django{420}-mysql]
 docker =
     testdb_mysql
 allowlist_externals =
@@ -61,7 +60,7 @@ commands_pre =
     sleep 25
     bash {toxinidir}/contrib/scripts/adjust_mysql_auth_plugin.sh root pass
 
-[testenv:{py39,py310}-django{320}-mariadb]
+[testenv:{py39,py310}-django{420}-mariadb]
 docker =
     testdb_mariadb
 allowlist_externals =
@@ -88,7 +87,7 @@ environment =
     POSTGRES_PASSWORD=nitrate
     POSTGRES_DB=testdb
 
-[testenv:{py39,py310}-django{320}-postgres]
+[testenv:{py39,py310}-django{420}-postgres]
 docker =
     testdb_postgres
 allowlist_externals =
@@ -175,11 +174,11 @@ skip_install = true
 deps = bandit==1.7.4
 commands = bandit -r {posargs:src/tcms}
 
-[testenv:mypy-django{320}]
+[testenv:mypy-django{420}]
 deps =
      {[testenv]deps}
-     django320: django-stubs==1.12.0
-     django320: mypy==0.971
+     django420: django-stubs==4.2.7
+     django420: mypy>=1.7,<1.8
 usedevelop = True
 extras =
     {[testenv]extras}