diff --git a/.travis.yml b/.travis.yml
index 6a8073df..1b79bc79 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,7 @@ language: python
 python:
     - 3.7
     - 3.8
+    - 3.9
 services:
     - postgresql
     - mysql
@@ -15,6 +16,9 @@ env:
     - DJANGO=3.0 DATABASE_ENGINE=sqlite
     - DJANGO=3.0 DATABASE_ENGINE=postgres
     - DJANGO=3.0 DATABASE_ENGINE=mysql
+    - DJANGO=4.0 DATABASE_ENGINE=sqlite
+    - DJANGO=4.0 DATABASE_ENGINE=postgres
+    - DJANGO=4.0 DATABASE_ENGINE=mysql
 
 install:
     - pip install -U setuptools zc.buildout
diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 88994348..6a104b4c 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -9,7 +9,7 @@ Version 0.5.0, 6th March 2020:
 * Compatiblity fix for Django 2.2 and Django 3.0.
 
 Version 0.4.6, 14th October 2017:
---------------------------------
+---------------------------------
 
 * Fix IntegrityError while saving inconsistent tags
 * Update tag name length to use MAX_TAG_LENGTH setting
diff --git a/tagging/models.py b/tagging/models.py
index 02550eec..50995c8d 100644
--- a/tagging/models.py
+++ b/tagging/models.py
@@ -5,7 +5,8 @@
 from django.contrib.contenttypes.models import ContentType
 from django.db import connection
 from django.db import models
-from django.utils.encoding import smart_text
+from django.db.models.query_utils import Q
+from django.utils.encoding import smart_str
 from django.utils.translation import gettext_lazy as _
 
 from tagging import settings
@@ -155,8 +156,9 @@ def usage_for_model(self, model, counts=False, min_count=None,
             filters = {}
 
         queryset = model._default_manager.filter()
-        for f in filters.items():
-            queryset.query.add_filter(f)
+        for k, v in filters.items():
+            # Add support for both Django 4 and inferior versions
+            queryset.query.add_q(Q((k, v)))
         usage = self.usage_for_queryset(queryset, counts, min_count)
 
         return usage
@@ -519,4 +521,4 @@ class Meta:
         verbose_name_plural = _('tagged items')
 
     def __str__(self):
-        return '%s [%s]' % (smart_text(self.object), smart_text(self.tag))
+        return '%s [%s]' % (smart_str(self.object), smart_str(self.tag))
diff --git a/tagging/tests/urls.py b/tagging/tests/urls.py
index aa127d5f..7db3e7e1 100644
--- a/tagging/tests/urls.py
+++ b/tagging/tests/urls.py
@@ -1,5 +1,5 @@
 """Test urls for tagging."""
-from django.conf.urls import url
+from django.urls import re_path
 
 from tagging.tests.models import Article
 from tagging.views import TaggedObjectList
@@ -11,10 +11,10 @@ class StaticTaggedObjectList(TaggedObjectList):
 
 
 urlpatterns = [
-    url(r'^static/$', StaticTaggedObjectList.as_view()),
-    url(r'^static/related/$', StaticTaggedObjectList.as_view(
+    re_path(r'^static/$', StaticTaggedObjectList.as_view()),
+    re_path(r'^static/related/$', StaticTaggedObjectList.as_view(
         related_tags=True)),
-    url(r'^no-tag/$', TaggedObjectList.as_view(model=Article)),
-    url(r'^no-query-no-model/$', TaggedObjectList.as_view()),
-    url(r'^(?P<tag>[^/]+(?u))/$', TaggedObjectList.as_view(model=Article)),
+    re_path(r'^no-tag/$', TaggedObjectList.as_view(model=Article)),
+    re_path(r'^no-query-no-model/$', TaggedObjectList.as_view()),
+    re_path(r'^(?P<tag>[^/]+(?u))/$', TaggedObjectList.as_view(model=Article)),
 ]