diff --git a/.githooks/pre-commit b/.githooks/pre-commit
index 8bad880444..7bacec5447 100755
--- a/.githooks/pre-commit
+++ b/.githooks/pre-commit
@@ -2,7 +2,8 @@
 
 . .githooks/toolkit
 
-PRE_COMMIT_CHECKS=${PRE_COMMIT_CHECKS-"flake8 isort eslint headers"}
+#PRE_COMMIT_CHECKS=${PRE_COMMIT_CHECKS-"flake8 isort eslint headers"}
+PRE_COMMIT_CHECKS=${PRE_COMMIT_CHECKS-"flake8 isort headers"}
 
 hook_check_isort() {
     git diff HEAD~1 --name-only --diff-filter=MARC | { grep '.py$' || true; } | xargs --no-run-if-empty isort --check --diff --atomic
diff --git a/.githooks/pre-push b/.githooks/pre-push
index f425347ac7..0a98be355e 100755
--- a/.githooks/pre-push
+++ b/.githooks/pre-push
@@ -2,7 +2,8 @@
 
 . .githooks/toolkit
 
-PRE_PUSH_CHECKS=${PRE_PUSH_CHECKS-"flake8 isort eslint signature"}
+#PRE_PUSH_CHECKS=${PRE_PUSH_CHECKS-"flake8 isort eslint signature"}
+PRE_PUSH_CHECKS=${PRE_PUSH_CHECKS-"flake8 isort signature"}
 GIT_PARENT_BRANCH="${GIT_PARENT_BRANCH:-main}"
 
 hook_check_isort() {
diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index a7dfd3e72a..f2a7e27be5 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,7 +1,22 @@
 == Version 2.3 Work in progress (not released -- this is a draft) ==
 
+  UPGRADE NOTE :
+    - You should create a all new virtual environment based on Python 3.6+
+      (eg: "mkvirtualenv -p /usr/bin/python3XX" if you use 'mkvirtualenv')
+      and populate it with "pip install -e .[mysql|pgsql]" of course.
+    - Execute the well known commands "migrate", "generatemedia" & "creme_populate".
+
+  Users side :
+  ------------
+    # The version of Django has been upgraded to 3.0.
+
+
   Developers side :
   -----------------
+    - The version of Django is now "3.0".
+      You should probably read the following releases notes for Django versions :
+        - https://docs.djangoproject.com/en/3.2/releases/3.0/
+
 
     Non breaking changes :
     ----------------------
diff --git a/README.md b/README.md
index 2c2737178c..e8d310771d 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ virtual env, in order to keep the old one working).
  - These python packages :
    (exact versions of Python packages are indicated in the 'setup.cfg' file)
    - Mandatory :
-     - Django 2.2
+     - Django 3.0
      - redis 3.4
      - python-dateutil 2.8
      - bleach 3.1
@@ -92,7 +92,7 @@ Installation with 'pip':
  - You should probably use "virtualenv" (on a Python >= 3.6).
  - Creme should be installed using 'pip install -e .'
  - About DB server :
-   - If you use MySQL, you must add the 'mysql' flag:
+   - If you use MySQL/MariaDB, you must add the 'mysql' flag:
      'pip install .[mysql]'
    - For PostGreSQL, use 'pip install .[pgsql]' instead.
    - SQLite doesn't require a specific flag (see RECOMMENDATIONS).
diff --git a/creme/activities/tests/test_activity.py b/creme/activities/tests/test_activity.py
index cdefa3f4fd..e264a89cae 100644
--- a/creme/activities/tests/test_activity.py
+++ b/creme/activities/tests/test_activity.py
@@ -9,7 +9,7 @@
 from django.forms import ModelMultipleChoiceField
 from django.forms.utils import ValidationError
 from django.urls import reverse
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 from django.utils.timezone import now
 from django.utils.translation import gettext as _
 
@@ -2325,7 +2325,8 @@ def test_dl_ical(self):
         self.assertEqual('text/calendar', response['Content-Type'])
         self.assertEqual('attachment; filename=Calendar.ics', response['Content-Disposition'])
 
-        content = force_text(response.content)
+        # content = force_text(response.content)
+        content = force_str(response.content)
         self.assertStartsWith(
             content,
             'BEGIN:VCALENDAR\nVERSION:2.0\nPRODID:-//CremeCRM//CremeCRM//EN\n'
diff --git a/creme/billing/tests/test_convert.py b/creme/billing/tests/test_convert.py
index 3fa80dff28..6b2aac36c2 100644
--- a/creme/billing/tests/test_convert.py
+++ b/creme/billing/tests/test_convert.py
@@ -7,7 +7,7 @@
 from django.contrib.contenttypes.models import ContentType
 from django.db.models.query_utils import Q
 from django.urls import reverse
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 from django.utils.timezone import now
 from django.utils.translation import gettext as _
 
@@ -214,8 +214,9 @@ def test_convert02_ajax(self):
         self.assertEqual(1, SalesOrder.objects.count())
 
         self.assertEqual(
-            force_text(response.content),
-            SalesOrder.objects.first().get_absolute_url()
+            # force_text(response.content),
+            force_str(response.content),
+            SalesOrder.objects.first().get_absolute_url(),
         )
 
     @skipIfCustomQuote
diff --git a/creme/creme_core/apps.py b/creme/creme_core/apps.py
index a065639801..b33194416a 100644
--- a/creme/creme_core/apps.py
+++ b/creme/creme_core/apps.py
@@ -156,6 +156,10 @@ def ready(self):
         for fname in ('app_label', 'model'):
             get_ct_field(fname).set_tags(viewable=False)
 
+        # NB: the original prefix with app's name => ugly choices for final users
+        #     => use gettext+context had smooth translation instead
+        ContentType.__str__ = lambda this: this.name
+
 
 class CremeAppConfig(AppConfig):
     # True => App can be used by some services
diff --git a/creme/creme_core/management/commands/build_secret_key.py b/creme/creme_core/management/commands/build_secret_key.py
index 022f791d6b..c6c1ac50e6 100644
--- a/creme/creme_core/management/commands/build_secret_key.py
+++ b/creme/creme_core/management/commands/build_secret_key.py
@@ -49,7 +49,7 @@ def handle(self, **options):
             from hashlib import sha256
             from time import time
 
-            from django.utils.encoding import force_text
+            from django.utils.encoding import force_str  # force_text
 
             choice = random.choice
 
@@ -66,7 +66,8 @@ def handle(self, **options):
 
             random.seed(
                 sha256(
-                    f'{random.getstate()}{time()}{force_text(kb_seed)}'.encode('utf-8')
+                    # f'{random.getstate()}{time()}{force_text(kb_seed)}'.encode('utf-8')
+                    f'{random.getstate()}{time()}{force_str(kb_seed)}'.encode('utf-8')
                 ).digest()
             )
 
diff --git a/creme/creme_core/management/commands/creme_uninstall.py b/creme/creme_core/management/commands/creme_uninstall.py
index a9e958c357..ad688cbf6d 100644
--- a/creme/creme_core/management/commands/creme_uninstall.py
+++ b/creme/creme_core/management/commands/creme_uninstall.py
@@ -29,7 +29,7 @@
 from django.db import DEFAULT_DB_ALIAS, connections
 from django.db.migrations.recorder import MigrationRecorder
 from django.dispatch import receiver
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 
 from creme.creme_core.core.setting_key import setting_key_registry
 from creme.creme_core.gui.bricks import Brick
@@ -470,7 +470,8 @@ def _delete_tables(self, app_config, app_label, verbosity):
                     ' [KO] Original error: {error}.\n'
                     'Remaining tables:\n'
                     '{models}\n'.format(
-                        error=force_text(e),  # PostGreSQL returns localized errors...
+                        # error=force_text(e),  # PostGreSQL returns localized errors...
+                        error=force_str(e),  # PostGreSQL returns localized errors...
                         models='\n'.join(model._meta.db_table for model in models),
                     )
                 )
diff --git a/creme/creme_core/management/commands/entity_factory.py b/creme/creme_core/management/commands/entity_factory.py
index 64267c03e1..27d0fb966c 100644
--- a/creme/creme_core/management/commands/entity_factory.py
+++ b/creme/creme_core/management/commands/entity_factory.py
@@ -290,7 +290,6 @@ class Command(BaseCommand):
 
     SQL_OPTIMISERS = {
         'django.db.backends.mysql': OptimizeMySQLContext,
-        'django.db.backends.postgresql_psycopg2': OptimizePGSQLContext,
         'django.db.backends.postgresql': OptimizePGSQLContext,
         # TODO: other DBRMS ?
     }
diff --git a/creme/creme_core/management/commands/i18n_overload.py b/creme/creme_core/management/commands/i18n_overload.py
index 9c6873640e..9f027ede9a 100644
--- a/creme/creme_core/management/commands/i18n_overload.py
+++ b/creme/creme_core/management/commands/i18n_overload.py
@@ -2,7 +2,7 @@
 
 ################################################################################
 #
-# Copyright (c) 2009-2020 Hybird
+# Copyright (c) 2009-2021 Hybird
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -32,7 +32,7 @@
 from django.apps import apps
 from django.conf import settings
 from django.core.management.base import BaseCommand, CommandError
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str
 
 APP_NAME = 'locale_overload'  # TODO: can configure it with command options ??
 
@@ -181,7 +181,7 @@ def _overload_terms(self, language, verbosity, polib, file_name, *args):
                                                     .localize(datetime.now()) \
                                                     .strftime('%Y-%m-%d %H:%M%z')
 
-        terms = [smart_text(arg) for arg in args]
+        terms = [smart_str(arg) for arg in args]
         entry_count = 0
 
         for app_pofile in self._iter_pofiles(language, polib, file_name):
diff --git a/creme/creme_core/middleware/exceptions.py b/creme/creme_core/middleware/exceptions.py
index 7e04ead358..65ac510ebf 100644
--- a/creme/creme_core/middleware/exceptions.py
+++ b/creme/creme_core/middleware/exceptions.py
@@ -2,7 +2,7 @@
 
 ################################################################################
 #    Creme is a free/open-source Customer Relationship Management software
-#    Copyright (C) 2009-2020  Hybird
+#    Copyright (C) 2009-2021  Hybird
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU Affero General Public License as published by
@@ -25,7 +25,7 @@
 from django.http import Http404, HttpResponse
 from django.shortcuts import render
 from django.utils.deprecation import MiddlewareMixin
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 
 from creme.creme_core.core import exceptions as creme_exceptions
 
@@ -41,7 +41,8 @@ class _AlternativeErrorMiddleware(MiddlewareMixin):
 
     def process_exception(self, request, exception):
         if self.error is None or isinstance(exception, self.error):
-            msg = smart_text(exception)
+            # msg = smart_text(exception)
+            msg = smart_str(exception)
 
             if request.is_ajax():
                 if self.log_ajax:
@@ -52,9 +53,10 @@ def process_exception(self, request, exception):
             if self.template is None:
                 return
 
-            return render(request, self.template,
-                          {'error_message': msg}, status=self.status,
-                         )
+            return render(
+                request, self.template,
+                {'error_message': msg}, status=self.status,
+            )
 
 
 class BadRequestMiddleware(_AlternativeErrorMiddleware):
diff --git a/creme/creme_core/models/fields.py b/creme/creme_core/models/fields.py
index daa8167deb..d612a8a51c 100644
--- a/creme/creme_core/models/fields.py
+++ b/creme/creme_core/models/fields.py
@@ -198,6 +198,7 @@ def formfield(self, **kwargs):
 
 
 # TODO: factorise with CTypeForeignKey
+#       (NB: using <descriptor_class> is harder than just move __get__/__set__ in a class...)
 class CTypeOneToOneField(models.OneToOneField):
     def __init__(self, **kwargs):
         kwargs['to'] = 'contenttypes.ContentType'
diff --git a/creme/creme_core/templatetags/creme_core_tags.py b/creme/creme_core/templatetags/creme_core_tags.py
index fcb5d626ee..bc4bac38e4 100644
--- a/creme/creme_core/templatetags/creme_core_tags.py
+++ b/creme/creme_core/templatetags/creme_core_tags.py
@@ -31,7 +31,7 @@
 from django.template import Template, TemplateSyntaxError
 from django.template.defaulttags import TemplateLiteral
 from django.template.library import token_kwargs
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 from django.utils.html import escape, format_html_join
 from django.utils.safestring import mark_safe
 
@@ -658,7 +658,8 @@ def render(self, context):
             logger.warning('jsondatablock tag do not accept custom "type" attribute')
 
         attrs = ''.join(
-            f' {k}="{escape(force_text(v.resolve(context)))}"'
+            # f' {k}="{escape(force_text(v.resolve(context)))}"'
+            f' {k}="{escape(force_str(v.resolve(context)))}"'
             for k, v in kwargs.items()
         )
 
diff --git a/creme/creme_core/tests/gui/test_field_printers.py b/creme/creme_core/tests/gui/test_field_printers.py
index 2284246946..82bd905104 100644
--- a/creme/creme_core/tests/gui/test_field_printers.py
+++ b/creme/creme_core/tests/gui/test_field_printers.py
@@ -1119,7 +1119,8 @@ def test_registry_fk(self):
         self.assertEqual(str(casca.image), get_csv_val(casca, 'image', user))
 
         self.assertEqual(
-            '<p>Casca&#39;s selfie</p>',
+            # '<p>Casca&#39;s selfie</p>',
+            '<p>Casca&#x27;s selfie</p>',
             get_html_val(casca, 'image__description', user)
         )
         self.assertEqual(
@@ -1310,7 +1311,8 @@ def test_registry_credentials(self):
             get_html_val(judo, 'image', user)
         )
         self.assertEqual(
-            '<p>Judo&#39;s selfie</p>',
+            # '<p>Judo&#39;s selfie</p>',
+            '<p>Judo&#x27;s selfie</p>',
             get_html_val(judo, 'image__description', user)
         )
 
diff --git a/creme/creme_core/tests/models/test_custom_field.py b/creme/creme_core/tests/models/test_custom_field.py
index 6a7e4c2ab3..ec3db73d0e 100644
--- a/creme/creme_core/tests/models/test_custom_field.py
+++ b/creme/creme_core/tests/models/test_custom_field.py
@@ -517,12 +517,13 @@ def test_multi_enum02(self):
             entity=orga,
         )
 
-        with self.assertNumQueries(3):
+        # with self.assertNumQueries(3):
+        with self.assertNumQueries(2):
             cf_value.set_value_n_save([enum_value1, enum_value2])
 
         self.assertSetEqual(
             {enum_value1, enum_value2},
-            {*self.refresh(cf_value).value.all()}
+            {*self.refresh(cf_value).value.all()},
         )
 
     def test_delete(self):
diff --git a/creme/creme_core/tests/views/test_job.py b/creme/creme_core/tests/views/test_job.py
index 67ecc6bcee..aedab93a34 100644
--- a/creme/creme_core/tests/views/test_job.py
+++ b/creme/creme_core/tests/views/test_job.py
@@ -6,7 +6,7 @@
 from django.db.models import Max
 from django.test.utils import override_settings
 from django.urls import reverse
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str
 from django.utils.formats import date_format
 from django.utils.timezone import localtime, now
 from django.utils.translation import gettext as _
@@ -51,7 +51,7 @@ def tearDown(self):
 
     # TODO: move to base class ?
     def _assertCount(self, response, found, count):
-        self.assertEqual(count, smart_text(response.content).count(found))
+        self.assertEqual(count, smart_str(response.content).count(found))
 
     def _build_enable_url(self, job):
         return reverse('creme_core__enable_job', args=(job.id,))
diff --git a/creme/creme_core/tests/views/test_listview.py b/creme/creme_core/tests/views/test_listview.py
index bfa2007474..c564fc3f5d 100644
--- a/creme/creme_core/tests/views/test_listview.py
+++ b/creme/creme_core/tests/views/test_listview.py
@@ -5,6 +5,7 @@
 from functools import partial
 from json import dumps as json_dump
 from random import shuffle
+from urllib.parse import quote
 from xml.etree.ElementTree import tostring as html_tostring
 
 from django.conf import settings
@@ -12,8 +13,8 @@
 from django.db.models import Q
 from django.test.utils import override_settings
 from django.urls import reverse
-from django.utils.encoding import force_text
-from django.utils.http import urlquote
+from django.utils.encoding import force_str  # force_text
+# from django.utils.http import urlquote
 from django.utils.timezone import now
 from django.utils.translation import gettext as _
 from django.utils.translation import pgettext
@@ -429,7 +430,8 @@ def post(selection):
             self.assertInHTML(
                 f'<input class="lv-state-field" value="{selection}" '
                 f'name="selection" type="hidden" />',
-                force_text(response.content),
+                # force_text(response.content),
+                force_str(response.content),
             )
 
         post('none')
@@ -450,7 +452,8 @@ def get(selection):
             self.assertInHTML(
                 f'<input class="lv-state-field" value="{selection}" '
                 f'name="selection" type="hidden" />',
-                force_text(response.content),
+                # force_text(response.content),
+                force_str(response.content),
             )
 
         get('none')
@@ -1003,7 +1006,8 @@ def test_ordering_fastmode_01(self):
             r'.creme_core_fakecontact.\..birthday. ASC( NULLS FIRST)?, '
             r'.creme_core_fakecontact.\..last_name. ASC( NULLS FIRST)?, '
             r'.creme_core_fakecontact.\..first_name. ASC( NULLS FIRST)?, '
-            r'.creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)?  LIMIT'
+            # r'.creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)?  LIMIT'
+            r'.creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)? LIMIT'
         )
 
     @override_settings(FAST_QUERY_MODE_THRESHOLD=2)
@@ -1014,7 +1018,8 @@ def test_ordering_fastmode_02(self):
             sql,
             r'ORDER BY'
             r' .creme_core_fakecontact.\..birthday. ASC( NULLS FIRST)?,'
-            r' .creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)?  LIMIT'
+            # r' .creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)?  LIMIT'
+            r' .creme_core_fakecontact.\..cremeentity_ptr_id. ASC( NULLS FIRST)? LIMIT'
         )
 
     def test_efilter01(self):
@@ -1176,8 +1181,10 @@ def test_header_buttons(self):
         dl_uri = data_hrefs[1]
         self.assertStartsWith(dl_uri, dl_url)
         self.assertIn(f'hfilter={hf.id}', dl_uri)
-        self.assertIn(f'&extra_q={urlquote(q_filter)}', dl_uri)
-        self.assertIn(f'&search-regular_field-phone={urlquote(searched_phone)}', dl_uri)
+        # self.assertIn(f'&extra_q={urlquote(q_filter)}', dl_uri)
+        self.assertIn(f'&extra_q={quote(q_filter)}', dl_uri)
+        # self.assertIn(f'&search-regular_field-phone={urlquote(searched_phone)}', dl_uri)
+        self.assertIn(f'&search-regular_field-phone={quote(searched_phone)}', dl_uri)
 
         dl_header_uri = data_hrefs[2]
         self.assertStartsWith(dl_header_uri, dl_url)
diff --git a/creme/creme_core/tests/views/test_mass_export.py b/creme/creme_core/tests/views/test_mass_export.py
index 72feedcf5a..dd06cf46b0 100644
--- a/creme/creme_core/tests/views/test_mass_export.py
+++ b/creme/creme_core/tests/views/test_mass_export.py
@@ -10,7 +10,7 @@
 from django.db.models import Q
 from django.test.utils import override_settings
 from django.urls import reverse
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str
 from django.utils.formats import date_format
 from django.utils.timezone import localtime
 from django.utils.translation import gettext as _
@@ -205,7 +205,7 @@ def test_list_view_export_header(self):
 
         self.assertListEqual(
             [','.join(f'"{hfi.title}"' for hfi in cells)],
-            [force_text(line) for line in response.content.splitlines()],
+            [force_str(line) for line in response.content.splitlines()],
         )
         self.assertFalse(HistoryLine.objects.exclude(id__in=existing_hline_ids))
 
@@ -232,7 +232,7 @@ def test_list_view_export01(self):
 
         # TODO: sort the relations/properties by their verbose_name ??
         result = response.content.splitlines()
-        it = (force_text(line) for line in result)
+        it = (force_str(line) for line in result)
         self.assertEqual(next(it), ','.join(f'"{hfi.title}"' for hfi in hf.cells))
         self.assertEqual(next(it), '"","Black","Jet","Bebop",""')
         self.assertIn(
@@ -286,7 +286,7 @@ def test_list_view_export02(self):
         response = self.assertGET200(self._build_contact_dl_url(doc_type='scsv'))
 
         # TODO: sort the relations/properties by their verbose_name ??
-        it = (force_text(line) for line in response.content.splitlines())
+        it = (force_str(line) for line in response.content.splitlines())
         self.assertEqual(next(it), ';'.join(f'"{hfi.title}"' for hfi in cells))
         self.assertEqual(next(it), '"";"Black";"Jet";"Bebop";""')
         self.assertIn(
@@ -340,7 +340,7 @@ def test_list_view_export04(self):
         self.assertTrue(user.has_perm_to_view(organisations['Swordfish']))
 
         response = self.assertGET200(self._build_contact_dl_url())
-        result = [*map(force_text, response.content.splitlines())]
+        result = [*map(force_str, response.content.splitlines())]
         self.assertEqual(result[1], '"","Black","Jet","",""')
         self.assertEqual(result[2], '"","Spiegel","Spike","Swordfish",""')
         self.assertEqual(result[3], '"","Wong","Edward","","is a girl"')
@@ -361,7 +361,7 @@ def test_list_view_export05(self):
 
         response = self.assertGET200(self._build_contact_dl_url(hfilter_id=hf.id))
 
-        result = [force_text(line) for line in response.content.splitlines()]
+        result = [force_str(line) for line in response.content.splitlines()]
         self.assertEqual(2, len(result))
         self.assertEqual(
             result[1],
@@ -401,7 +401,7 @@ def test_list_view_export06(self):
         )
 
         response = self.assertGET200(self._build_contact_dl_url(hfilter_id=hf.id))
-        it = (force_text(line) for line in response.content.splitlines()); next(it)
+        it = (force_str(line) for line in response.content.splitlines()); next(it)
 
         self.assertEqual(next(it), '"Black","Jet face","Jet\'s selfie"')
 
@@ -435,7 +435,7 @@ def test_list_view_export07(self):
             list_url=FakeEmailCampaign.get_lv_absolute_url(),
             hfilter_id=hf.id,
         ))
-        result = [force_text(line) for line in response.content.splitlines()]
+        result = [force_str(line) for line in response.content.splitlines()]
         self.assertEqual(4, len(result))
 
         self.assertEqual(result[1], '"Camp#1","ML#1/ML#2"')
@@ -454,7 +454,7 @@ def test_list_view_export08(self):
 
         response = self.assertGET200(self._build_contact_dl_url())
 
-        it = (force_text(line) for line in response.content.splitlines())
+        it = (force_str(line) for line in response.content.splitlines())
         self.assertEqual(
             next(it),
             ','.join(
@@ -472,7 +472,7 @@ def test_extra_filter(self):
             self._build_contact_dl_url(extra_q=QSerializer().dumps(Q(last_name='Wong'))),
         )
 
-        result = [force_text(line) for line in response.content.splitlines()]
+        result = [force_str(line) for line in response.content.splitlines()]
         self.assertEqual(2, len(result))
         self.assertEqual('"","Wong","Edward","","is a girl"', result[1])
 
@@ -496,7 +496,7 @@ def test_list_view_export_with_filter01(self):
             list_url=FakeContact.get_lv_absolute_url(),
             efilter_id=efilter.id
         ))
-        result = [force_text(line) for line in response.content.splitlines()]
+        result = [force_str(line) for line in response.content.splitlines()]
         self.assertEqual(2, len(result))
 
         self.assertEqual('"","Wong","Edward","","is a girl"', result[1])
@@ -628,7 +628,7 @@ def test_print_integer01(self):
             follow=True,
         )
 
-        lines = {force_text(line) for line in response.content.splitlines()}
+        lines = {force_str(line) for line in response.content.splitlines()}
         self.assertIn('"Bebop","1000"', lines)
         self.assertIn('"Swordfish","20000"', lines)
         self.assertIn('"Redtail",""', lines)
@@ -661,7 +661,7 @@ def test_print_integer02(self):
             follow=True,
         )
 
-        lines = {force_text(line) for line in response.content.splitlines()}
+        lines = {force_str(line) for line in response.content.splitlines()}
         self.assertIn('"Bebop","{}"'.format(_('Percent')),    lines)
         self.assertIn('"Swordfish","{}"'.format(_('Amount')), lines)
 
@@ -723,7 +723,7 @@ def test_quick_search(self):
                 '"123233","Spiegel","Spike"',
             ],
             # NB: slice to remove the header
-            [force_text(line) for line in response.content.splitlines()[1:]]
+            [force_str(line) for line in response.content.splitlines()[1:]]
         )
 
     @override_settings(PAGE_SIZES=[10], DEFAULT_PAGE_SIZE_IDX=0)
@@ -758,7 +758,7 @@ def test_sorting(self):
                 '"123455","Black","Jet"',
             ],
             # NB: slice to remove the header
-            [force_text(line) for line in response.content.splitlines()[1:]]
+            [force_str(line) for line in response.content.splitlines()[1:]]
         )
 
     def test_distinct(self):
diff --git a/creme/creme_core/tests/views/test_mass_import.py b/creme/creme_core/tests/views/test_mass_import.py
index ed56c381fe..82dbb42c74 100644
--- a/creme/creme_core/tests/views/test_mass_import.py
+++ b/creme/creme_core/tests/views/test_mass_import.py
@@ -8,7 +8,7 @@
 from django.template.defaultfilters import slugify
 from django.test.utils import override_settings
 from django.urls import reverse
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str
 from django.utils.timezone import now
 from django.utils.translation import gettext as _
 from django.utils.translation import ngettext
@@ -1579,7 +1579,7 @@ def _csv_to_list(response):
 
         return [
             [i[1:-1] for i in line.split(separator)]
-            for line in smart_text(response.content).splitlines()
+            for line in smart_str(response.content).splitlines()
         ]
 
     def test_dl_errors01(self):
diff --git a/creme/creme_core/utils/html.py b/creme/creme_core/utils/html.py
index 599092ddcb..925c0f1e8a 100644
--- a/creme/creme_core/utils/html.py
+++ b/creme/creme_core/utils/html.py
@@ -22,7 +22,7 @@
 
 import bleach
 from django.conf import settings
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 from django.utils.html import mark_safe
 
 _AllowedAttributesDict = Dict[str, Union[Sequence[str], Callable[[str, str, str], bool]]]
@@ -114,4 +114,5 @@ def sanitize_html(html: str, allow_external_img: bool = False) -> str:
 
 
 def escapejson(value: str) -> str:
-    return mark_safe(force_text(value).translate(JSON_ESCAPES))
+    # return mark_safe(force_text(value).translate(JSON_ESCAPES))
+    return mark_safe(force_str(value).translate(JSON_ESCAPES))
diff --git a/creme/creme_core/views/entity.py b/creme/creme_core/views/entity.py
index f6a18284d3..387f7d1d56 100644
--- a/creme/creme_core/views/entity.py
+++ b/creme/creme_core/views/entity.py
@@ -32,10 +32,12 @@
 from django.http import Http404, HttpResponse, HttpResponseBadRequest
 from django.shortcuts import get_object_or_404, redirect, render
 from django.urls import reverse
+from django.utils.decorators import method_decorator
 from django.utils.html import format_html
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
 from django.utils.translation import ngettext
+from django.views.decorators.clickjacking import xframe_options_sameorigin
 
 from .. import constants
 from ..auth import SUPERUSER_PERM
@@ -107,6 +109,7 @@ def get_creme_entities_repr(request, entities_ids):
     ]
 
 
+@method_decorator(xframe_options_sameorigin, name='dispatch')
 class HTMLFieldSanitizing(generic.base.EntityRelatedMixin,
                           generic.CheckedView):
     """Used to show an HTML document in an <iframe>."""
diff --git a/creme/creme_core/views/exceptions.py b/creme/creme_core/views/exceptions.py
index b3f68307fa..43a2fe7f9e 100644
--- a/creme/creme_core/views/exceptions.py
+++ b/creme/creme_core/views/exceptions.py
@@ -20,7 +20,7 @@
 
 from django.http import HttpResponseForbidden
 from django.template.loader import render_to_string
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 from django.views.decorators.csrf import requires_csrf_token
 
 
@@ -28,6 +28,7 @@
 def permission_denied(request, exception, template_name='creme_core/forbidden.html'):
     return HttpResponseForbidden(render_to_string(
         template_name,
-        {'error_message': smart_text(exception)},
+        # {'error_message': smart_text(exception)},
+        {'error_message': smart_str(exception)},
         request=request,
     ))
diff --git a/creme/creme_core/views/job.py b/creme/creme_core/views/job.py
index 19099898d3..2bbdb4018c 100644
--- a/creme/creme_core/views/job.py
+++ b/creme/creme_core/views/job.py
@@ -22,7 +22,7 @@
 from django.http import Http404, HttpResponse
 from django.shortcuts import get_object_or_404
 from django.urls import reverse
-from django.utils.http import is_safe_url
+from django.utils.http import url_has_allowed_host_and_scheme  # is_safe_url
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
 
@@ -65,7 +65,8 @@ def check_instance_permissions(self, instance, user):
     def get_list_url(self):
         request = self.request
         list_url = request.GET.get('list_url')
-        list_url_is_safe = list_url and is_safe_url(
+        # list_url_is_safe = list_url and is_safe_url(
+        list_url_is_safe = list_url and url_has_allowed_host_and_scheme(
             url=list_url,
             allowed_hosts={request.get_host()},
             require_https=request.is_secure(),
diff --git a/creme/documents/tests/test_document.py b/creme/documents/tests/test_document.py
index 4f0682cb71..defd691a65 100644
--- a/creme/documents/tests/test_document.py
+++ b/creme/documents/tests/test_document.py
@@ -664,8 +664,9 @@ def test_field_printers02(self):
             get_html_val(judo, 'image', other_user)
         )
         self.assertEqual(
-            '<p>Judo&#39;s selfie</p>',
-            get_html_val(judo, 'image__description', other_user)
+            # '<p>Judo&#39;s selfie</p>',
+            '<p>Judo&#x27;s selfie</p>',
+            get_html_val(judo, 'image__description', other_user),
         )
 
         HIDDEN_VALUE = settings.HIDDEN_VALUE
diff --git a/creme/emails/forms/recipient.py b/creme/emails/forms/recipient.py
index f6e54f1e52..e023b98f92 100644
--- a/creme/emails/forms/recipient.py
+++ b/creme/emails/forms/recipient.py
@@ -20,7 +20,7 @@
 
 from django.core.validators import validate_email
 from django.forms import FileField, ValidationError
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 from django.utils.translation import gettext_lazy as _
 
 from creme.creme_core.forms import CremeForm, FieldBlockManager
@@ -103,7 +103,8 @@ def __init__(self, entity, *args, **kwargs):
 
     @staticmethod
     def filter_mail_chunk(value):
-        result = smart_text(value.strip())
+        # result = smart_text(value.strip())
+        result = smart_str(value.strip())
 
         try:
             validate_email(result)
@@ -113,7 +114,7 @@ def filter_mail_chunk(value):
         return result
 
     def save(self):  # TODO: factorise with MailingListAddRecipientsForm.save() ??
-        ml      = self.ml
+        ml = self.ml
         create  = EmailRecipient.objects.create
         filter_ = EmailRecipient.objects.filter
 
diff --git a/creme/emails/tests/test_mail.py b/creme/emails/tests/test_mail.py
index c4cda92efb..1fc76af060 100644
--- a/creme/emails/tests/test_mail.py
+++ b/creme/emails/tests/test_mail.py
@@ -898,6 +898,7 @@ def test_get_sanitized_html_field01(self):
             reverse('creme_core__sanitized_html_field', args=(email.id, 'body_html'))
         )
         self.assertEqual(b'', response.content)
+        self.assertEqual('SAMEORIGIN', response.get('X-Frame-Options'))
 
     def test_get_sanitized_html_field02(self):
         self.login()
diff --git a/creme/emails/tests/test_sending.py b/creme/emails/tests/test_sending.py
index b8be41ce77..1503567041 100644
--- a/creme/emails/tests/test_sending.py
+++ b/creme/emails/tests/test_sending.py
@@ -305,31 +305,35 @@ def test_create01(self):
         mail = mails[0]
         self.assertEqual(0, mail.reads)
         self.assertEqual(MAIL_STATUS_NOTSENT, mail.status)
-        response = self.assertGET200(reverse('emails__view_lw_mail', args=(mail.id,)))
-        self.assertTemplateUsed(response, 'creme_core/generics/detail-popup.html')
-        self.assertEqual(_('Details of the email'), response.context.get('title'))
+
+        response1 = self.assertGET200(reverse('emails__view_lw_mail', args=(mail.id,)))
+        self.assertTemplateUsed(response1, 'creme_core/generics/detail-popup.html')
+        self.assertEqual(_('Details of the email'), response1.context.get('title'))
+        self.assertEqual('DENY', response1.get('X-Frame-Options'))
 
         # ---
-        response = self.assertGET200(reverse('emails__lw_mail_body', args=(mail.id,)))
-        self.assertEqual(b'', response.content)
+        response2 = self.assertGET200(reverse('emails__lw_mail_body', args=(mail.id,)))
+        self.assertEqual(b'', response2.content)
+        self.assertEqual('SAMEORIGIN', response2.get('X-Frame-Options'))
 
         # Detail view ----------------------------------------------------------
         detail_url = reverse('emails__view_sending', args=(sending.id,))
         self.assertPOST405(detail_url)
 
-        response = self.assertGET200(detail_url)
-        self.assertTemplateUsed(response, 'emails/view_sending.html')
-        self.assertEqual(sending, response.context.get('object'))
+        response3 = self.assertGET200(detail_url)
+        self.assertTemplateUsed(response3, 'emails/view_sending.html')
+        self.assertEqual(sending, response3.context.get('object'))
 
-        self.assertContains(response, contacts[0].email)
-        self.assertContains(response, orgas[0].email)
+        self.assertContains(response3, contacts[0].email)
+        self.assertContains(response3, orgas[0].email)
 
         # HTML body ----------------------------------------------------------
         body_url = reverse('emails__sending_body', args=(sending.id,))
         self.assertPOST405(body_url)
 
-        response = self.assertGET200(body_url)
-        self.assertEqual(b'', response.content)
+        response4 = self.assertGET200(body_url)
+        self.assertEqual(b'', response4.content)
+        self.assertEqual('SAMEORIGIN', response4.get('X-Frame-Options'))
 
         # Test delete campaign -------------------------------------------------
         camp.trash()
diff --git a/creme/emails/views/mail.py b/creme/emails/views/mail.py
index cbce9a9a20..336d6c596e 100644
--- a/creme/emails/views/mail.py
+++ b/creme/emails/views/mail.py
@@ -24,8 +24,10 @@
 from django.http import HttpResponse
 from django.shortcuts import get_object_or_404
 from django.template import Context, Template
+from django.utils.decorators import method_decorator
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
+from django.views.decorators.clickjacking import xframe_options_sameorigin
 
 from creme.creme_core.auth import build_creation_perm as cperm
 from creme.creme_core.core.exceptions import ConflictError
@@ -206,6 +208,7 @@ def get_brick_ids(self):
         )
 
 
+@method_decorator(xframe_options_sameorigin, name='dispatch')
 class LightWeightEmailBody(generic.CheckedView):
     """Used to show an HTML document in an <iframe>."""
     permissions = 'emails'
diff --git a/creme/emails/views/sending.py b/creme/emails/views/sending.py
index 58a7bfd910..9a7a9fbc2a 100644
--- a/creme/emails/views/sending.py
+++ b/creme/emails/views/sending.py
@@ -20,7 +20,9 @@
 
 from django.http import Http404, HttpResponse
 from django.shortcuts import get_object_or_404
+from django.utils.decorators import method_decorator
 from django.utils.translation import gettext_lazy as _
+from django.views.decorators.clickjacking import xframe_options_sameorigin
 
 from creme.creme_core.utils.html import sanitize_html
 from creme.creme_core.views import bricks as bricks_views
@@ -48,6 +50,7 @@ class SendingDetail(generic.RelatedToEntityDetail):
 
 
 # TODO: factorise with get_lightweight_mail_body()
+@method_decorator(xframe_options_sameorigin, name='dispatch')
 class SendingBody(generic.RelatedToEntityDetail):
     model = EmailSending
     pk_url_kwarg = 'sending_id'
diff --git a/creme/graphs/forms/root_node.py b/creme/graphs/forms/root_node.py
index a945210804..7c80bddf52 100644
--- a/creme/graphs/forms/root_node.py
+++ b/creme/graphs/forms/root_node.py
@@ -2,7 +2,7 @@
 
 ################################################################################
 #    Creme is a free/open-source Customer Relationship Management software
-#    Copyright (C) 2009-2020  Hybird
+#    Copyright (C) 2009-2021  Hybird
 #
 #    This program is free software: you can redistribute it and/or modify
 #    it under the terms of the GNU Affero General Public License as published by
@@ -19,7 +19,7 @@
 ################################################################################
 
 from django.forms import ModelMultipleChoiceField
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 from django.utils.translation import gettext_lazy as _
 
 from creme.creme_core.forms import CremeForm, CremeModelForm
@@ -31,14 +31,15 @@
 
 class RelationTypeMultipleChoiceField(ModelMultipleChoiceField):
     def label_from_instance(self, obj):
-        return smart_text(obj.predicate)
+        # return smart_text(obj.predicate)
+        return smart_str(obj.predicate)
 
 
 class AddRootNodesForm(CremeForm):
-    entities       = MultiGenericEntityField(label=_('Root entities'))
-    relation_types = RelationTypeMultipleChoiceField(label=_('Related types of relations'),
-                                                     queryset=RelationType.objects.all(),
-                                                    )
+    entities = MultiGenericEntityField(label=_('Root entities'))
+    relation_types = RelationTypeMultipleChoiceField(
+        label=_('Related types of relations'), queryset=RelationType.objects.all(),
+    )
 
     def __init__(self, entity, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -59,9 +60,9 @@ def save(self):
 
 
 class EditRootNodeForm(CremeModelForm):
-    relation_types = RelationTypeMultipleChoiceField(label=_('Related types of relations'),
-                                                     queryset=RelationType.objects.all(),
-                                                     )
+    relation_types = RelationTypeMultipleChoiceField(
+        label=_('Related types of relations'), queryset=RelationType.objects.all(),
+    )
 
     class Meta:
         model = RootNode
diff --git a/creme/mobile/views.py b/creme/mobile/views.py
index 594a4f9c04..8e80c19eb5 100644
--- a/creme/mobile/views.py
+++ b/creme/mobile/views.py
@@ -31,7 +31,7 @@
 from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
 from django.utils.decorators import method_decorator
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 from django.utils.timezone import localtime, now
 from django.utils.translation import gettext as _
 from django.views.decorators.http import require_POST
@@ -102,7 +102,8 @@ def _aux(request, *args, **kwargs):
             {
                 'status':    status,
                 'msg':       msg,
-                'exception': smart_text(error),
+                # 'exception': smart_text(error),
+                'exception': smart_str(error),
             },
             status=status,
         )
@@ -214,16 +215,16 @@ def persons_portal(request):
         request, 'mobile/directory.html',
         {
             'favorite_contacts': cred_filter(
-                Contact.objects.filter(is_deleted=False,
-                                       mobile_favorite__user=user,
-                                      )
+                Contact.objects.filter(
+                    is_deleted=False, mobile_favorite__user=user,
+                )
             ),
             'contact_model': Contact,
 
             'favorite_organisations': cred_filter(
-                Organisation.objects.filter(is_deleted=False,
-                                            mobile_favorite__user=user,
-                                           )
+                Organisation.objects.filter(
+                    is_deleted=False, mobile_favorite__user=user,
+                )
             ),
             'orga_model': Organisation,
         },
diff --git a/creme/polls/tests/test_poll_form.py b/creme/polls/tests/test_poll_form.py
index 2ea356b2b7..327f4cd61d 100644
--- a/creme/polls/tests/test_poll_form.py
+++ b/creme/polls/tests/test_poll_form.py
@@ -6,7 +6,7 @@
 
 from django.contrib.contenttypes.models import ContentType
 from django.urls import reverse
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str
 from django.utils.translation import gettext as _
 from parameterized import parameterized
 
@@ -464,7 +464,7 @@ def test_delete_section04(self):
         self.assertStillExists(line)
         self.assertEqual(
             _('There is at least one question in this section.'),
-            smart_text(response.content)
+            smart_str(response.content),
         )
 
     def test_add_line_string01(self):
@@ -1995,7 +1995,7 @@ def test_disable_line_ajax02(self):
         self.assertStillExists(cond)
         self.assertEqual(
             _('There is at least one other question which depends on this question.'),
-            smart_text(response.content),
+            smart_str(response.content),
         )
 
     def test_delete_line01(self):
@@ -2087,7 +2087,7 @@ def test_delete_line_ajax02(self):
         self.assertStillExists(cond)
         self.assertEqual(
             _('There is at least one other question which depends on this question.'),
-            smart_text(response.content)
+            smart_str(response.content),
         )
 
     def test_get_choices01(self):
diff --git a/creme/sms/forms/recipient.py b/creme/sms/forms/recipient.py
index f17c077244..db7d5ef7d1 100644
--- a/creme/sms/forms/recipient.py
+++ b/creme/sms/forms/recipient.py
@@ -19,7 +19,7 @@
 ################################################################################
 
 from django.forms import FileField, Textarea
-from django.utils.encoding import smart_text
+from django.utils.encoding import smart_str  # smart_text
 from django.utils.translation import gettext_lazy as _
 
 from creme.creme_core.forms import CremeForm, FieldBlockManager
@@ -86,7 +86,8 @@ def save(self):
         # TODO: genexpr
         def phones():
             for line in uploaded_file:
-                phone = PhoneField.filternumbers(smart_text(line.strip()))
+                # phone = PhoneField.filternumbers(smart_text(line.strip()))
+                phone = PhoneField.filternumbers(smart_str(line.strip()))
                 if phone:
                     yield phone
 
diff --git a/doc/en/Tutorial - Code a module.rst b/doc/en/Tutorial - Code a module.rst
index 7a9cde72df..9a25ed2584 100644
--- a/doc/en/Tutorial - Code a module.rst	
+++ b/doc/en/Tutorial - Code a module.rst	
@@ -3,7 +3,7 @@ Developer's notebook for Creme modules
 ======================================
 
 :Author: Guillaume Englert
-:Version: 29-01-2021 for Creme 2.2
+:Version: 29-01-2021 for Creme 2.3
 :Copyright: Hybird
 :License: GNU FREE DOCUMENTATION LICENSE version 1.3
 :Errata: Hugo Smett, Patix
@@ -29,8 +29,8 @@ Requirements
 
 Creme is developed with a Python framework for websites et Web apps : Django_.
 If you really want to code some modules for Creme, you should know Django.
-Its documentation is complete & quite good ; see here : https://docs.djangoproject.com/en/2.2/.
-To begin, reading the `tutorial <https://docs.djangoproject.com/en/2.2/intro/overview/>`_
+Its documentation is complete & quite good ; see here : https://docs.djangoproject.com/en/3.0/.
+To begin, reading the `tutorial <https://docs.djangoproject.com/en/3.0/intro/overview/>`_
 should be enough.
 
 Creme uses the JavaScript (JS) library jQuery_ too ; to implement some features
diff --git a/doc/fr/Didacticiel - Coder un module.rst b/doc/fr/Didacticiel - Coder un module.rst
index 134f1a0ec0..03867e94ec 100644
--- a/doc/fr/Didacticiel - Coder un module.rst	
+++ b/doc/fr/Didacticiel - Coder un module.rst	
@@ -3,7 +3,7 @@ Carnet du développeur de modules Creme
 ======================================
 
 :Author: Guillaume Englert
-:Version: 29-01-2021 pour la version 2.2 de Creme
+:Version: 29-01-2021 pour la version 2.3 de Creme
 :Copyright: Hybird
 :License: GNU FREE DOCUMENTATION LICENSE version 1.3
 :Errata: Hugo Smett, Patix
@@ -30,8 +30,8 @@ Creme est développé en utilisant un cadriciel (framework) Python spécialisé
 la création de sites et applications Web : Django_.
 Si vous comptez réellement développer des modules pour Creme, la connaissance de
 Django sera sûrement nécessaire. Heureusement la documentation de celui-ci est vraiment
-complète et bien faite ; vous la trouverez ici : https://docs.djangoproject.com/fr/2.2/.
-Dans un premier temps, avoir lu le `didacticiel <https://docs.djangoproject.com/fr/2.2/intro/overview/>`_
+complète et bien faite ; vous la trouverez ici : https://docs.djangoproject.com/fr/3.0/.
+Dans un premier temps, avoir lu le `didacticiel <https://docs.djangoproject.com/fr/3.0/intro/overview/>`_
 devrait suffire.
 
 Creme utilise aussi la bibliothèque JavaScript (JS) jQuery_ ; il se peut que pour
diff --git a/mediagenerator/api.py b/mediagenerator/api.py
index bed8b24257..f5e3befbbb 100644
--- a/mediagenerator/api.py
+++ b/mediagenerator/api.py
@@ -1,12 +1,16 @@
-from collections import defaultdict, OrderedDict
 import logging
 import os
 import shutil
+from collections import OrderedDict, defaultdict
+from urllib.parse import quote
 
-from django.utils.http import urlquote
-
+# from django.utils.http import urlquote
 from . import utils  # settings
-from .settings import GENERATED_MEDIA_DIR, GENERATED_MEDIA_NAMES_FILE, MEDIA_GENERATORS
+from .settings import (
+    GENERATED_MEDIA_DIR,
+    GENERATED_MEDIA_NAMES_FILE,
+    MEDIA_GENERATORS,
+)
 from .utils import load_backend
 
 # HACK: by Hybird (we should pass it as argument -- & modify all the API)
@@ -42,7 +46,8 @@ def generate_media():
             with open(path, 'wb') as fp:
                 fp.write(content)
 
-            utils.NAMES[key] = urlquote(url)
+            # utils.NAMES[key] = urlquote(url)
+            utils.NAMES[key] = quote(url)
 
     # Generate a module with media file name mappings
     with open(GENERATED_MEDIA_NAMES_FILE, 'w') as fp:
diff --git a/mediagenerator/settings.py b/mediagenerator/settings.py
index 7701a0e918..bf1508d250 100644
--- a/mediagenerator/settings.py
+++ b/mediagenerator/settings.py
@@ -1,8 +1,8 @@
-from os import path as os_path
 import sys
+from os import path as os_path
 
 from django.conf import settings
-from django.utils.encoding import force_text
+from django.utils.encoding import force_str  # force_text
 
 __main__ = sys.modules.get('__main__')
 
@@ -15,16 +15,17 @@
     _media_dir = os_path.join(_root, _media_dir)
 
 GENERATED_MEDIA_DIR = os_path.abspath(getattr(settings, 'GENERATED_MEDIA_DIR', _media_dir))
-GENERATED_MEDIA_NAMES_MODULE = getattr(settings, 'GENERATED_MEDIA_NAMES_MODULE',
-                                       '_generated_media_names'
-                                      )
+GENERATED_MEDIA_NAMES_MODULE = getattr(
+    settings, 'GENERATED_MEDIA_NAMES_MODULE', '_generated_media_names'
+)
 GENERATED_MEDIA_NAMES_FILE = os_path.abspath(
     getattr(settings, 'GENERATED_MEDIA_NAMES_FILE', _map_file_path)
 )
 
-PRODUCTION_MEDIA_URL = getattr(settings, 'PRODUCTION_MEDIA_URL',
-                               getattr(settings, 'STATIC_URL', settings.MEDIA_URL)
-                              )
+PRODUCTION_MEDIA_URL = getattr(
+    settings, 'PRODUCTION_MEDIA_URL',
+    getattr(settings, 'STATIC_URL', settings.MEDIA_URL)
+)
 
 MEDIA_GENERATORS = getattr(settings, 'MEDIA_GENERATORS', (
     'mediagenerator.generators.copyfiles.CopyFiles',
@@ -33,10 +34,11 @@
 ))
 
 GLOBAL_MEDIA_DIRS = [
-    os_path.normcase(os_path.normpath(force_text(path)))
-        for path in getattr(settings, 'GLOBAL_MEDIA_DIRS',
-                            getattr(settings, 'STATICFILES_DIRS', ())
-                           )
+    # os_path.normcase(os_path.normpath(force_text(path)))
+    os_path.normcase(os_path.normpath(force_str(path)))
+    for path in getattr(
+        settings, 'GLOBAL_MEDIA_DIRS', getattr(settings, 'STATICFILES_DIRS', ())
+    )
 ]
 
 IGNORE_APP_MEDIA_DIRS = getattr(settings, 'IGNORE_APP_MEDIA_DIRS', ('django.contrib.admin',))
diff --git a/mediagenerator/utils.py b/mediagenerator/utils.py
index 1f18a1d4b8..4f61bd9dbd 100644
--- a/mediagenerator/utils.py
+++ b/mediagenerator/utils.py
@@ -1,18 +1,21 @@
 # -*- coding: utf-8 -*-
 
-from os import path as os_path
-from importlib import import_module
 import re
+from importlib import import_module
+from os import path as os_path
+from urllib.parse import quote
 
+# from django.utils.http import urlquote
 from django.apps import apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
-from django.utils.http import urlquote
 
 from .settings import (
-    GLOBAL_MEDIA_DIRS, PRODUCTION_MEDIA_URL,
-    IGNORE_APP_MEDIA_DIRS, MEDIA_GENERATORS,
     GENERATED_MEDIA_NAMES_MODULE,
+    GLOBAL_MEDIA_DIRS,
+    IGNORE_APP_MEDIA_DIRS,
+    MEDIA_GENERATORS,
+    PRODUCTION_MEDIA_URL,
 )
 
 try:
@@ -43,7 +46,8 @@ def _refresh_dev_names():
 
     for backend in _load_generators():
         for key, url, hash in backend.get_dev_output_names():
-            versioned_url = urlquote(url)
+            # versioned_url = urlquote(url)
+            versioned_url = quote(url)
 
             if hash:
                 versioned_url += '?version=' + hash
@@ -129,8 +133,8 @@ def get_media_dirs():
             if app.name in IGNORE_APP_MEDIA_DIRS:
                 continue
 
-            media_dirs.append(os_path.join(app.path, u'static'))
-            media_dirs.append(os_path.join(app.path, u'media'))
+            media_dirs.append(os_path.join(app.path, 'static'))
+            media_dirs.append(os_path.join(app.path, 'media'))
 
         _media_dirs_cache.extend(media_dirs)
 
diff --git a/setup.cfg b/setup.cfg
index ed306a8e39..7e682ed2e3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -31,7 +31,7 @@ zip_safe = False
 include_package_data = True
 packages = find:
 install_requires =
-    django ~=2.2.17
+    django ~=3.0.11
     redis ~=3.4.1
     Pillow ~=7.2.0
     python-dateutil ~=2.8.1