diff --git a/polymorphic/tests/__init__.py b/polymorphic/tests/__init__.py
index e69de29b..3d112022 100644
--- a/polymorphic/tests/__init__.py
+++ b/polymorphic/tests/__init__.py
@@ -0,0 +1,6 @@
+import django
+
+if django.VERSION < (4, 2):  # TODO: remove when dropping support for Django < 4.2
+    from django.test.testcases import TransactionTestCase
+
+    TransactionTestCase.assertQuerySetEqual = TransactionTestCase.assertQuerysetEqual
diff --git a/polymorphic/tests/test_multidb.py b/polymorphic/tests/test_multidb.py
index 716b3f96..192bb778 100644
--- a/polymorphic/tests/test_multidb.py
+++ b/polymorphic/tests/test_multidb.py
@@ -26,13 +26,13 @@ def test_save_to_non_default_database(self):
         Model2B.objects.create(field1="B1", field2="B2")
         Model2D(field1="D1", field2="D2", field3="D3", field4="D4").save()
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Model2A.objects.order_by("id"),
             [Model2B, Model2D],
             transform=lambda o: o.__class__,
         )
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Model2A.objects.db_manager("secondary").order_by("id"),
             [Model2A, Model2C],
             transform=lambda o: o.__class__,
@@ -44,26 +44,26 @@ def test_instance_of_filter_on_non_default_database(self):
         ModelY.objects.db_manager("secondary").create(field_b="Y", field_y="Y")
 
         objects = Base.objects.db_manager("secondary").filter(instance_of=Base)
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Base, ModelX, ModelY],
             transform=lambda o: o.__class__,
             ordered=False,
         )
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Base.objects.db_manager("secondary").filter(instance_of=ModelX),
             [ModelX],
             transform=lambda o: o.__class__,
         )
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Base.objects.db_manager("secondary").filter(instance_of=ModelY),
             [ModelY],
             transform=lambda o: o.__class__,
         )
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Base.objects.db_manager("secondary").filter(
                 Q(instance_of=ModelX) | Q(instance_of=ModelY)
             ),
diff --git a/polymorphic/tests/test_orm.py b/polymorphic/tests/test_orm.py
index 3c38f202..61f7d242 100644
--- a/polymorphic/tests/test_orm.py
+++ b/polymorphic/tests/test_orm.py
@@ -222,7 +222,7 @@ def test_simple_inheritance(self):
         self.create_model2abcd()
 
         objects = Model2A.objects.all()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2A, Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -324,7 +324,7 @@ def test_non_polymorphic(self):
         self.create_model2abcd()
 
         objects = list(Model2A.objects.all().non_polymorphic())
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2A, Model2A, Model2A, Model2A],
             transform=lambda o: o.__class__,
@@ -336,7 +336,7 @@ def test_get_real_instances(self):
 
         # from queryset
         objects = qs.get_real_instances()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2A, Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -344,7 +344,7 @@ def test_get_real_instances(self):
 
         # from a manual list
         objects = Model2A.objects.get_real_instances(list(qs))
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2A, Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -352,7 +352,7 @@ def test_get_real_instances(self):
 
         # from empty list
         objects = Model2A.objects.get_real_instances([])
-        self.assertQuerysetEqual(objects, [], transform=lambda o: o.__class__)
+        self.assertQuerySetEqual(objects, [], transform=lambda o: o.__class__)
 
     def test_queryset_missing_derived(self):
         a = Model2A.objects.create(field1="A1")
@@ -389,7 +389,7 @@ def test_translate_polymorphic_q_object(self):
 
         q = Model2A.translate_polymorphic_Q_object(Q(instance_of=Model2C))
         objects = Model2A.objects.filter(q)
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects, [Model2C, Model2D], transform=lambda o: o.__class__, ordered=False
         )
 
@@ -505,7 +505,7 @@ def test_manytomany_field(self):
         # no pretty printing
         ModelShow1_plain.objects.create(field1="abc")
         ModelShow2_plain.objects.create(field1="abc", field2="def")
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             ModelShow1_plain.objects.all(),
             [ModelShow1_plain, ModelShow2_plain],
             transform=lambda o: o.__class__,
@@ -516,7 +516,7 @@ def test_extra_method(self):
         a, b, c, d = self.create_model2abcd()
 
         objects = Model2A.objects.extra(where=[f"id IN ({b.id}, {c.id})"])
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects, [Model2B, Model2C], transform=lambda o: o.__class__, ordered=False
         )
 
@@ -525,7 +525,7 @@ def test_extra_method(self):
             where=["field1 = 'A1' OR field1 = 'B1'"],
             order_by=["-id"],
         )
-        self.assertQuerysetEqual(objects, [Model2B, Model2A], transform=lambda o: o.__class__)
+        self.assertQuerySetEqual(objects, [Model2B, Model2A], transform=lambda o: o.__class__)
 
         ModelExtraA.objects.create(field1="A1")
         ModelExtraB.objects.create(field1="B1", field2="B2")
@@ -556,7 +556,7 @@ def test_instance_of_filter(self):
         self.create_model2abcd()
 
         objects = Model2A.objects.instance_of(Model2B)
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -564,7 +564,7 @@ def test_instance_of_filter(self):
         )
 
         objects = Model2A.objects.filter(instance_of=Model2B)
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -572,7 +572,7 @@ def test_instance_of_filter(self):
         )
 
         objects = Model2A.objects.filter(Q(instance_of=Model2B))
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2B, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -580,7 +580,7 @@ def test_instance_of_filter(self):
         )
 
         objects = Model2A.objects.not_instance_of(Model2B)
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects, [Model2A], transform=lambda o: o.__class__, ordered=False
         )
 
@@ -588,7 +588,7 @@ def test_polymorphic___filter(self):
         self.create_model2abcd()
 
         objects = Model2A.objects.filter(Q(Model2B___field2="B2") | Q(Model2C___field3="C3"))
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects, [Model2B, Model2C], transform=lambda o: o.__class__, ordered=False
         )
 
@@ -599,7 +599,7 @@ def test_polymorphic_applabel___filter(self):
         objects = Model2A.objects.filter(
             Q(tests__Model2B___field2="B2") | Q(tests__Model2C___field3="C3")
         )
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects, [Model2B, Model2C], transform=lambda o: o.__class__, ordered=False
         )
 
@@ -645,7 +645,7 @@ def test_delete(self):
 
         oa.delete()
         objects = Model2A.objects.all()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [Model2A, Model2C, Model2D],
             transform=lambda o: o.__class__,
@@ -748,7 +748,7 @@ def test_user_defined_manager(self):
 
         # MyManager should reverse the sorting of field1
         objects = ModelWithMyManager.objects.all()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [(ModelWithMyManager, "D1b", "D4b"), (ModelWithMyManager, "D1a", "D4a")],
             transform=lambda o: (o.__class__, o.field1, o.field4),
@@ -764,7 +764,7 @@ def test_user_defined_manager_as_secondary(self):
 
         # MyManager should reverse the sorting of field1
         objects = ModelWithMyManagerNoDefault.my_objects.all()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [
                 (ModelWithMyManagerNoDefault, "D1b", "D4b"),
@@ -792,7 +792,7 @@ def test_user_defined_queryset_as_manager(self):
         ModelWithMyManager2.objects.create(field1="D1b", field4="D4b")
 
         objects = ModelWithMyManager2.objects.all()
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             objects,
             [(ModelWithMyManager2, "D1a", "D4a"), (ModelWithMyManager2, "D1b", "D4b")],
             transform=lambda o: (o.__class__, o.field1, o.field4),
diff --git a/polymorphic/tests/test_regression.py b/polymorphic/tests/test_regression.py
index e416f4fb..0f48971e 100644
--- a/polymorphic/tests/test_regression.py
+++ b/polymorphic/tests/test_regression.py
@@ -18,16 +18,16 @@ def test_for_query_result_incomplete_with_inheritance(self):
         bottom.save()
 
         expected_queryset = [top, middle, bottom]
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Top.objects.order_by("pk"), [repr(r) for r in expected_queryset], **transform_arg
         )
 
         expected_queryset = [middle, bottom]
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Middle.objects.order_by("pk"), [repr(r) for r in expected_queryset], **transform_arg
         )
 
         expected_queryset = [bottom]
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Bottom.objects.order_by("pk"), [repr(r) for r in expected_queryset], **transform_arg
         )
diff --git a/polymorphic/tests/test_utils.py b/polymorphic/tests/test_utils.py
index 1495ea02..0934a507 100644
--- a/polymorphic/tests/test_utils.py
+++ b/polymorphic/tests/test_utils.py
@@ -38,7 +38,7 @@ def test_reset_polymorphic_ctype(self):
 
         reset_polymorphic_ctype(Model2D, Model2B, Model2D, Model2A, Model2C)
 
-        self.assertQuerysetEqual(
+        self.assertQuerySetEqual(
             Model2A.objects.order_by("pk"),
             [Model2A, Model2D, Model2B, Model2B],
             transform=lambda o: o.__class__,