diff --git a/django/http/multipartparser.py b/django/http/multipartparser.py
index 543fc4a552..7b45404d9d 100644
--- a/django/http/multipartparser.py
+++ b/django/http/multipartparser.py
@@ -69,7 +69,7 @@ class MultiPartParser:
         ctypes, opts = parse_header(content_type.encode('ascii'))
         boundary = opts.get('boundary')
         if not boundary or not cgi.valid_boundary(boundary):
-            raise MultiPartParserError('Invalid boundary in multipart: %s' % boundary)
+            raise MultiPartParserError('Invalid boundary in multipart: %s' % boundary.decode())
 
         # Content-Length should contain the length of the body we are about
         # to receive.
diff --git a/tests/forms_tests/field_tests/test_choicefield.py b/tests/forms_tests/field_tests/test_choicefield.py
index f500c18680..fd382e47ca 100644
--- a/tests/forms_tests/field_tests/test_choicefield.py
+++ b/tests/forms_tests/field_tests/test_choicefield.py
@@ -1,5 +1,5 @@
 from django.forms import ChoiceField, Form, ValidationError
-from django.test import SimpleTestCase, ignore_warnings
+from django.test import SimpleTestCase
 
 from . import FormFieldAssertionsMixin
 
@@ -82,16 +82,3 @@ class ChoiceFieldTest(FormFieldAssertionsMixin, SimpleTestCase):
             '<select id="id_f" name="f" disabled><option value="J">John</option>'
             '<option value="P">Paul</option></select>'
         )
-
-    @ignore_warnings(category=UnicodeWarning)
-    def test_utf8_bytesrings(self):
-        # Choice validation with UTF-8 bytestrings as input (these are the
-        # Russian abbreviations "мес." and "шт.".
-        f = ChoiceField(
-            choices=(
-                (b'\xd0\xbc\xd0\xb5\xd1\x81.', b'\xd0\xbc\xd0\xb5\xd1\x81.'),
-                (b'\xd1\x88\xd1\x82.', b'\xd1\x88\xd1\x82.'),
-            ),
-        )
-        self.assertEqual(f.clean('\u0448\u0442.'), '\u0448\u0442.')
-        self.assertEqual(f.clean(b'\xd1\x88\xd1\x82.'), '\u0448\u0442.')
diff --git a/tests/view_tests/tests/test_debug.py b/tests/view_tests/tests/test_debug.py
index 8d8d5a57a4..9b0feab8ea 100644
--- a/tests/view_tests/tests/test_debug.py
+++ b/tests/view_tests/tests/test_debug.py
@@ -140,7 +140,7 @@ class DebugViewTests(LoggingCaptureMixin, SimpleTestCase):
             id_repr = match.group('id')
             self.assertFalse(
                 re.search(b'[^c0-9]', id_repr),
-                "Numeric IDs in debug response HTML page shouldn't be localized (value: %s)." % id_repr
+                "Numeric IDs in debug response HTML page shouldn't be localized (value: %s)." % id_repr.decode()
             )
 
     def test_template_exceptions(self):
diff --git a/tests/view_tests/tests/test_defaults.py b/tests/view_tests/tests/test_defaults.py
index 3ab109a57c..b36d5b5b58 100644
--- a/tests/view_tests/tests/test_defaults.py
+++ b/tests/view_tests/tests/test_defaults.py
@@ -64,8 +64,8 @@ class DefaultsTests(TestCase):
         # See ticket #14565
         for url in self.nonexistent_urls:
             response = self.client.get(url)
-            self.assertNotEqual(response.content, 'NOTPROVIDED')
-            self.assertNotEqual(response.content, '')
+            self.assertNotEqual(response.content, b'NOTPROVIDED')
+            self.assertNotEqual(response.content, b'')
 
     def test_server_error(self):
         "The server_error view raises a 500 status"