diff --git a/tests/__init__.py b/tests/__init__.py
index e74afd28..e4bb1e3a 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -4,7 +4,6 @@ import time
 import json
 import shutil
 import tempfile
-import unittest
 try:
     from unittest import skipIf, skip
 except ImportError:
@@ -26,7 +25,7 @@ sys.path.insert(0, os.path.realpath(os.path.join(TESTS_ROOT, '..')))
 from httpie import ExitStatus
 from httpie.models import Environment
 from httpie.core import main
-from httpie.compat import is_py26, bytes, str
+from httpie.compat import bytes, str
 
 
 def patharg(path):
@@ -39,7 +38,7 @@ HTTPBIN_URL = os.environ.get('HTTPBIN_URL',
 
 
 CRLF = '\r\n'
-OK = 'HTTP/1.1 200'
+HTTP_OK = 'HTTP/1.1 200'
 OK_COLOR = (
     'HTTP\x1b[39m\x1b[38;5;245m/\x1b[39m\x1b'
     '[38;5;37m1.1\x1b[39m\x1b[38;5;245m \x1b[39m\x1b[38;5;37m200'
@@ -189,22 +188,3 @@ def http(*args, **kwargs):
     finally:
         stdout.close()
         stderr.close()
-
-
-class BaseTestCase(unittest.TestCase):
-
-    maxDiff = 100000
-
-    if is_py26:
-        def assertIn(self, member, container, msg=None):
-            self.assertTrue(member in container, msg)
-
-        def assertNotIn(self, member, container, msg=None):
-            self.assertTrue(member not in container, msg)
-
-        def assertDictEqual(self, d1, d2, msg=None):
-            self.assertEqual(set(d1.keys()), set(d2.keys()), msg)
-            self.assertEqual(sorted(d1.values()), sorted(d2.values()), msg)
-
-    def assertIsNone(self, obj, msg=None):
-        self.assertEqual(obj, None, msg=msg)
diff --git a/tests/test_auth.py b/tests/test_auth.py
index 3ccdb9ec..f2da290d 100644
--- a/tests/test_auth.py
+++ b/tests/test_auth.py
@@ -1,11 +1,13 @@
 """HTTP authentication-related tests."""
+from unittest import TestCase
+
 import requests
 
-from tests import BaseTestCase, http, httpbin, OK, skipIf
+from tests import http, httpbin, HTTP_OK, skipIf
 import httpie.input
 
 
-class AuthTest(BaseTestCase):
+class AuthTest(TestCase):
 
     def test_basic_auth(self):
         r = http(
@@ -13,9 +15,9 @@ class AuthTest(BaseTestCase):
             'GET',
             httpbin('/basic-auth/user/password')
         )
-        self.assertIn(OK, r)
-        self.assertIn('"authenticated": true', r)
-        self.assertIn('"user": "user"', r)
+        assert HTTP_OK in r
+        assert '"authenticated": true' in r
+        assert '"user": "user"' in r
 
     @skipIf(requests.__version__ == '0.13.6',
             'Redirects with prefetch=False are broken in Requests 0.13.6')
@@ -26,9 +28,9 @@ class AuthTest(BaseTestCase):
             'GET',
             httpbin('/digest-auth/auth/user/password')
         )
-        self.assertIn(OK, r)
-        self.assertIn(r'"authenticated": true', r)
-        self.assertIn(r'"user": "user"', r)
+        assert HTTP_OK in r
+        assert r'"authenticated": true' in r
+        assert r'"user": "user"', r
 
     def test_password_prompt(self):
 
@@ -41,9 +43,9 @@ class AuthTest(BaseTestCase):
             httpbin('/basic-auth/user/password')
         )
 
-        self.assertIn(OK, r)
-        self.assertIn('"authenticated": true', r)
-        self.assertIn('"user": "user"', r)
+        assert HTTP_OK in r
+        assert '"authenticated": true' in r
+        assert '"user": "user"' in r
 
     def test_credentials_in_url(self):
         url = httpbin('/basic-auth/user/password')
@@ -52,9 +54,9 @@ class AuthTest(BaseTestCase):
             'GET',
             url
         )
-        self.assertIn(OK, r)
-        self.assertIn('"authenticated": true', r)
-        self.assertIn('"user": "user"', r)
+        assert HTTP_OK in r
+        assert '"authenticated": true'in r
+        assert '"user": "user"' in r
 
     def test_credentials_in_url_auth_flag_has_priority(self):
         """When credentials are passed in URL and via -a at the same time,
@@ -66,6 +68,6 @@ class AuthTest(BaseTestCase):
             'GET',
             url
         )
-        self.assertIn(OK, r)
-        self.assertIn('"authenticated": true', r)
-        self.assertIn('"user": "user"', r)
+        assert HTTP_OK in r
+        assert '"authenticated": true' in r
+        assert '"user": "user"' in r
diff --git a/tests/test_binary.py b/tests/test_binary.py
index fd6e700f..35d0cfa1 100644
--- a/tests/test_binary.py
+++ b/tests/test_binary.py
@@ -1,14 +1,16 @@
 """Tests for dealing with binary request and response data."""
+from unittest import TestCase
+
 from httpie.compat import urlopen
 from httpie.output import BINARY_SUPPRESSED_NOTICE
 from tests import (
-    BaseTestCase, TestEnvironment, http, httpbin,
+    TestEnvironment, http, httpbin,
     BIN_FILE_PATH, BIN_FILE_CONTENT, BIN_FILE_PATH_ARG,
 
 )
 
 
-class BinaryRequestDataTest(BaseTestCase):
+class BinaryRequestDataTest(TestCase):
 
     def test_binary_stdin(self):
         with open(BIN_FILE_PATH, 'rb') as stdin:
@@ -23,7 +25,7 @@ class BinaryRequestDataTest(BaseTestCase):
                 httpbin('/post'),
                 env=env,
             )
-            self.assertEqual(r, BIN_FILE_CONTENT)
+            assert r == BIN_FILE_CONTENT
 
     def test_binary_file_path(self):
         env = TestEnvironment(
@@ -38,7 +40,7 @@ class BinaryRequestDataTest(BaseTestCase):
             env=env,
         )
 
-        self.assertEqual(r, BIN_FILE_CONTENT)
+        assert r == BIN_FILE_CONTENT
 
     def test_binary_file_form(self):
         env = TestEnvironment(
@@ -53,10 +55,10 @@ class BinaryRequestDataTest(BaseTestCase):
             'test@' + BIN_FILE_PATH_ARG,
             env=env,
         )
-        self.assertIn(bytes(BIN_FILE_CONTENT), bytes(r))
+        assert bytes(BIN_FILE_CONTENT) in bytes(r)
 
 
-class BinaryResponseDataTest(BaseTestCase):
+class BinaryResponseDataTest(TestCase):
 
     url = 'http://www.google.com/favicon.ico'
 
@@ -71,7 +73,7 @@ class BinaryResponseDataTest(BaseTestCase):
             'GET',
             self.url
         )
-        self.assertIn(BINARY_SUPPRESSED_NOTICE.decode(), r)
+        assert BINARY_SUPPRESSED_NOTICE.decode() in r
 
     def test_binary_suppresses_when_not_terminal_but_pretty(self):
         r = http(
@@ -81,7 +83,7 @@ class BinaryResponseDataTest(BaseTestCase):
             env=TestEnvironment(stdin_isatty=True,
                             stdout_isatty=False)
         )
-        self.assertIn(BINARY_SUPPRESSED_NOTICE.decode(), r)
+        assert BINARY_SUPPRESSED_NOTICE.decode() in r
 
     def test_binary_included_and_correct_when_suitable(self):
         r = http(
@@ -90,4 +92,4 @@ class BinaryResponseDataTest(BaseTestCase):
             env=TestEnvironment(stdin_isatty=True,
                             stdout_isatty=False)
         )
-        self.assertEqual(r, self.bindata)
+        assert r == self.bindata
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 71e277b1..feeb084c 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -1,23 +1,25 @@
 """CLI argument parsing related tests."""
 import json
+from unittest import TestCase
 
 # noinspection PyCompatibility
 import argparse
 
 from tests import (
-    BaseTestCase, TestEnvironment, http, httpbin,
+    TestEnvironment, http, httpbin,
     FILE_PATH_ARG, JSON_FILE_PATH_ARG,
-    JSON_FILE_CONTENT, FILE_CONTENT, OK, FILE_PATH
+    JSON_FILE_CONTENT, FILE_CONTENT, HTTP_OK, FILE_PATH
 )
 from httpie import input
+from httpie.input import KeyValue, KeyValueArgType
 from httpie import ExitStatus
 from httpie.cli import parser
 
 
-class ItemParsingTest(BaseTestCase):
+class ItemParsingTest(TestCase):
 
     def setUp(self):
-        self.key_value_type = input.KeyValueArgType(
+        self.key_value_type = KeyValueArgType(
             *input.SEP_GROUP_ALL_ITEMS
         )
 
@@ -39,22 +41,18 @@ class ItemParsingTest(BaseTestCase):
         ])
         # `requests.structures.CaseInsensitiveDict` => `dict`
         headers = dict(headers._store.values())
-        self.assertDictEqual(headers, {
+        assert headers == {
             'foo:bar': 'baz',
             'jack@jill': 'hill',
-        })
-        self.assertDictEqual(data, {
-            'baz=bar': 'foo',
-        })
-        self.assertIn('bar@baz', files)
+        }
+        assert data == {'baz=bar': 'foo'}
+        assert 'bar@baz' in files
 
     def test_escape_longsep(self):
         headers, data, files, params = input.parse_items([
             self.key_value_type('bob\\:==foo'),
         ])
-        self.assertDictEqual(params, {
-            'bob:': 'foo',
-        })
+        assert params == {'bob:': 'foo'}
 
     def test_valid_items(self):
         headers, data, files, params = input.parse_items([
@@ -74,37 +72,31 @@ class ItemParsingTest(BaseTestCase):
         # Parsed headers
         # `requests.structures.CaseInsensitiveDict` => `dict`
         headers = dict(headers._store.values())
-        self.assertDictEqual(headers, {
-            'header': 'value',
-            'eh': ''
-        })
+        assert headers == {'header': 'value', 'eh': ''}
 
         # Parsed data
         raw_json_embed = data.pop('raw-json-embed')
-        self.assertDictEqual(raw_json_embed, json.loads(
-            JSON_FILE_CONTENT.decode('utf8')))
+        assert raw_json_embed == json.loads(
+            JSON_FILE_CONTENT.decode('utf8'))
         data['string-embed'] = data['string-embed'].strip()
-        self.assertDictEqual(dict(data), {
+        assert dict(data) == {
             "ed": "",
             "string": "value",
             "bool": True,
             "list": ["a", 1, {}, False],
             "obj": {"a": "b"},
             "string-embed": FILE_CONTENT,
-        })
+        }
 
         # Parsed query string parameters
-        self.assertDictEqual(params, {
-            'query': 'value',
-        })
+        assert params == {'query': 'value'}
 
         # Parsed file fields
-        self.assertIn('file', files)
-        self.assertEqual(files['file'][1].read().strip().decode('utf8'),
-                         FILE_CONTENT)
+        assert 'file' in files
+        assert files['file'][1].read().strip().decode('utf8') == FILE_CONTENT
 
 
-class QuerystringTest(BaseTestCase):
+class QuerystringTest(TestCase):
 
     def test_query_string_params_in_url(self):
         r = http(
@@ -116,9 +108,9 @@ class QuerystringTest(BaseTestCase):
         path = '/get?a=1&b=2'
         url = httpbin(path)
 
-        self.assertIn(OK, r)
-        self.assertIn('GET %s HTTP/1.1' % path, r)
-        self.assertIn('"url": "%s"' % url, r)
+        assert HTTP_OK in r
+        assert 'GET %s HTTP/1.1' % path in r
+        assert '"url": "%s"' % url in r
 
     def test_query_string_params_items(self):
         r = http(
@@ -132,9 +124,9 @@ class QuerystringTest(BaseTestCase):
         path = '/get?a=1&b=2'
         url = httpbin(path)
 
-        self.assertIn(OK, r)
-        self.assertIn('GET %s HTTP/1.1' % path, r)
-        self.assertIn('"url": "%s"' % url, r)
+        assert HTTP_OK in r
+        assert 'GET %s HTTP/1.1' % path in r
+        assert '"url": "%s"' % url in r
 
     def test_query_string_params_in_url_and_items_with_duplicates(self):
         r = http(
@@ -149,68 +141,57 @@ class QuerystringTest(BaseTestCase):
         path = '/get?a=1&a=1&a=1&a=1&b=2'
         url = httpbin(path)
 
-        self.assertIn(OK, r)
-        self.assertIn('GET %s HTTP/1.1' % path, r)
-        self.assertIn('"url": "%s"' % url, r)
+        assert HTTP_OK in r
+        assert 'GET %s HTTP/1.1' % path in r
+        assert '"url": "%s"' % url in r
 
 
-class CLIParserTestCase(BaseTestCase):
+class CLIParserTestCase(TestCase):
 
     def test_expand_localhost_shorthand(self):
         args = parser.parse_args(args=[':'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost')
+        assert args.url == 'http://localhost'
 
     def test_expand_localhost_shorthand_with_slash(self):
         args = parser.parse_args(args=[':/'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost/')
+        assert args.url == 'http://localhost/'
 
     def test_expand_localhost_shorthand_with_port(self):
         args = parser.parse_args(args=[':3000'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost:3000')
+        assert args.url == 'http://localhost:3000'
 
     def test_expand_localhost_shorthand_with_path(self):
         args = parser.parse_args(args=[':/path'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost/path')
+        assert args.url == 'http://localhost/path'
 
     def test_expand_localhost_shorthand_with_port_and_slash(self):
         args = parser.parse_args(args=[':3000/'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost:3000/')
+        assert args.url == 'http://localhost:3000/'
 
     def test_expand_localhost_shorthand_with_port_and_path(self):
         args = parser.parse_args(args=[':3000/path'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://localhost:3000/path')
+        assert args.url == 'http://localhost:3000/path'
 
     def test_dont_expand_shorthand_ipv6_as_shorthand(self):
         args = parser.parse_args(args=['::1'], env=TestEnvironment())
-
-        self.assertEqual(args.url, 'http://::1')
+        assert args.url == 'http://::1'
 
     def test_dont_expand_longer_ipv6_as_shorthand(self):
         args = parser.parse_args(
             args=['::ffff:c000:0280'],
             env=TestEnvironment()
         )
-        self.assertEqual(args.url, 'http://::ffff:c000:0280')
+        assert args.url == 'http://::ffff:c000:0280'
 
     def test_dont_expand_full_ipv6_as_shorthand(self):
         args = parser.parse_args(
             args=['0000:0000:0000:0000:0000:0000:0000:0001'],
             env=TestEnvironment()
         )
-
-        self.assertEqual(
-            args.url,
-            'http://0000:0000:0000:0000:0000:0000:0000:0001'
-        )
+        assert args.url == 'http://0000:0000:0000:0000:0000:0000:0000:0001'
 
 
-class ArgumentParserTestCase(BaseTestCase):
+class ArgumentParserTestCase(TestCase):
 
     def setUp(self):
         self.parser = input.Parser()
@@ -226,9 +207,9 @@ class ArgumentParserTestCase(BaseTestCase):
 
         self.parser._guess_method()
 
-        self.assertEqual(self.parser.args.method, 'GET')
-        self.assertEqual(self.parser.args.url, 'http://example.com/')
-        self.assertEqual(self.parser.args.items, [])
+        assert self.parser.args.method == 'GET'
+        assert self.parser.args.url == 'http://example.com/'
+        assert self.parser.args.items == []
 
     def test_guess_when_method_not_set(self):
 
@@ -241,9 +222,9 @@ class ArgumentParserTestCase(BaseTestCase):
 
         self.parser._guess_method()
 
-        self.assertEqual(self.parser.args.method, 'GET')
-        self.assertEqual(self.parser.args.url, 'http://example.com/')
-        self.assertEqual(self.parser.args.items, [])
+        assert self.parser.args.method == 'GET'
+        assert self.parser.args.url == 'http://example.com/'
+        assert self.parser.args.items == []
 
     def test_guess_when_method_set_but_invalid_and_data_field(self):
         self.parser.args = argparse.Namespace()
@@ -254,12 +235,14 @@ class ArgumentParserTestCase(BaseTestCase):
         self.parser.env = TestEnvironment()
         self.parser._guess_method()
 
-        self.assertEqual(self.parser.args.method, 'POST')
-        self.assertEqual(self.parser.args.url, 'http://example.com/')
-        self.assertEqual(
-            self.parser.args.items,
-            [input.KeyValue(
-                key='data', value='field', sep='=', orig='data=field')])
+        assert self.parser.args.method == 'POST'
+        assert self.parser.args.url == 'http://example.com/'
+        assert self.parser.args.items == [
+            KeyValue(key='data',
+                           value='field',
+                           sep='=',
+                           orig='data=field')
+        ]
 
     def test_guess_when_method_set_but_invalid_and_header_field(self):
         self.parser.args = argparse.Namespace()
@@ -272,19 +255,21 @@ class ArgumentParserTestCase(BaseTestCase):
 
         self.parser._guess_method()
 
-        self.assertEqual(self.parser.args.method, 'GET')
-        self.assertEqual(self.parser.args.url, 'http://example.com/')
-        self.assertEqual(
-            self.parser.args.items,
-            [input.KeyValue(
-                key='test', value='header', sep=':', orig='test:header')])
+        assert self.parser.args.method == 'GET'
+        assert self.parser.args.url == 'http://example.com/'
+        assert self.parser.args.items, [
+            KeyValue(key='test',
+                           value='header',
+                           sep=':',
+                           orig='test:header')
+        ]
 
     def test_guess_when_method_set_but_invalid_and_item_exists(self):
         self.parser.args = argparse.Namespace()
         self.parser.args.method = 'http://example.com/'
         self.parser.args.url = 'new_item=a'
         self.parser.args.items = [
-            input.KeyValue(
+            KeyValue(
                 key='old_item', value='b', sep='=', orig='old_item=b')
         ]
         self.parser.args.ignore_stdin = False
@@ -293,15 +278,14 @@ class ArgumentParserTestCase(BaseTestCase):
 
         self.parser._guess_method()
 
-        self.assertEqual(self.parser.args.items, [
-            input.KeyValue(
-                key='new_item', value='a', sep='=', orig='new_item=a'),
-            input.KeyValue(
+        assert self.parser.args.items, [
+            KeyValue(key='new_item', value='a', sep='=', orig='new_item=a'),
+            KeyValue(
                 key='old_item', value='b', sep='=', orig='old_item=b'),
-        ])
+        ]
 
 
-class TestNoOptions(BaseTestCase):
+class TestNoOptions(TestCase):
 
     def test_valid_no_options(self):
         r = http(
@@ -310,7 +294,7 @@ class TestNoOptions(BaseTestCase):
             'GET',
             httpbin('/get')
         )
-        self.assertNotIn('GET /get HTTP/1.1', r)
+        assert 'GET /get HTTP/1.1' not in r
 
     def test_invalid_no_options(self):
         r = http(
@@ -318,12 +302,12 @@ class TestNoOptions(BaseTestCase):
             'GET',
             httpbin('/get')
         )
-        self.assertEqual(r.exit_status, 1)
-        self.assertIn('unrecognized arguments: --no-war', r.stderr)
-        self.assertNotIn('GET /get HTTP/1.1', r)
+        assert r.exit_status == 1
+        assert 'unrecognized arguments: --no-war' in r.stderr
+        assert 'GET /get HTTP/1.1' not in r
 
 
-class IgnoreStdinTest(BaseTestCase):
+class IgnoreStdinTest(TestCase):
 
     def test_ignore_stdin(self):
         with open(FILE_PATH) as f:
@@ -333,9 +317,9 @@ class IgnoreStdinTest(BaseTestCase):
                 httpbin('/get'),
                 env=TestEnvironment(stdin=f, stdin_isatty=False)
             )
-        self.assertIn(OK, r)
-        self.assertIn('GET /get HTTP', r)  # Don't default to POST.
-        self.assertNotIn(FILE_CONTENT, r)  # Don't send stdin data.
+        assert HTTP_OK in r
+        assert 'GET /get HTTP' in r, "Don't default to POST."
+        assert FILE_CONTENT not in r, "Don't send stdin data."
 
     def test_ignore_stdin_cannot_prompt_password(self):
         r = http(
@@ -343,5 +327,5 @@ class IgnoreStdinTest(BaseTestCase):
             '--auth=username-without-password',
             httpbin('/get'),
         )
-        self.assertEqual(r.exit_status, ExitStatus.ERROR)
-        self.assertIn('because --ignore-stdin', r.stderr)
+        assert r.exit_status == ExitStatus.ERROR
+        assert 'because --ignore-stdin' in r.stderr
diff --git a/tests/test_defaults.py b/tests/test_defaults.py
index ddaba1cb..d80354ba 100644
--- a/tests/test_defaults.py
+++ b/tests/test_defaults.py
@@ -2,34 +2,36 @@
 Tests for the provided defaults regarding HTTP method, and --json vs. --form.
 
 """
+from unittest import TestCase
+
 from tests import (
-    BaseTestCase, TestEnvironment,
+    TestEnvironment,
     http, httpbin,
-    OK, FILE_PATH,
+    HTTP_OK, FILE_PATH,
 )
 
 
-class ImplicitHTTPMethodTest(BaseTestCase):
+class ImplicitHTTPMethodTest(TestCase):
 
     def test_implicit_GET(self):
         r = http(httpbin('/get'))
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
     def test_implicit_GET_with_headers(self):
         r = http(
             httpbin('/headers'),
             'Foo:bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Foo": "bar"', r)
+        assert HTTP_OK in r
+        assert '"Foo": "bar"' in r
 
     def test_implicit_POST_json(self):
         r = http(
             httpbin('/post'),
             'hello=world'
         )
-        self.assertIn(OK, r)
-        self.assertIn(r'\"hello\": \"world\"', r)
+        assert HTTP_OK in r
+        assert r'\"hello\": \"world\"' in r
 
     def test_implicit_POST_form(self):
         r = http(
@@ -37,8 +39,8 @@ class ImplicitHTTPMethodTest(BaseTestCase):
             httpbin('/post'),
             'foo=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"foo": "bar"', r)
+        assert HTTP_OK in r
+        assert '"foo": "bar"' in r
 
     def test_implicit_POST_stdin(self):
         with open(FILE_PATH) as f:
@@ -51,10 +53,10 @@ class ImplicitHTTPMethodTest(BaseTestCase):
                 httpbin('/post'),
                 env=env
             )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
 
-class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
+class AutoContentTypeAndAcceptHeadersTest(TestCase):
     """
     Test that Accept and Content-Type correctly defaults to JSON,
     but can still be overridden. The same with Content-Type when --form
@@ -67,9 +69,9 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             'GET',
             httpbin('/headers')
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Accept": "*/*"', r)
-        self.assertNotIn('"Content-Type": "application/json', r)
+        assert HTTP_OK in r
+        assert '"Accept": "*/*"' in r
+        assert '"Content-Type": "application/json' not in r
 
     def test_POST_no_data_no_auto_headers(self):
         # JSON headers shouldn't be automatically set for POST with no data.
@@ -77,9 +79,9 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             'POST',
             httpbin('/post')
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Accept": "*/*"', r)
-        self.assertNotIn('"Content-Type": "application/json', r)
+        assert HTTP_OK in r
+        assert '"Accept": "*/*"' in r
+        assert '"Content-Type": "application/json' not in r
 
     def test_POST_with_data_auto_JSON_headers(self):
         r = http(
@@ -87,9 +89,9 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             httpbin('/post'),
             'a=b'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Accept": "application/json"', r)
-        self.assertIn('"Content-Type": "application/json; charset=utf-8', r)
+        assert HTTP_OK in r
+        assert '"Accept": "application/json"' in r
+        assert '"Content-Type": "application/json; charset=utf-8' in r
 
     def test_GET_with_data_auto_JSON_headers(self):
         # JSON headers should automatically be set also for GET with data.
@@ -98,9 +100,9 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             httpbin('/post'),
             'a=b'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Accept": "application/json"', r)
-        self.assertIn('"Content-Type": "application/json; charset=utf-8', r)
+        assert HTTP_OK in r
+        assert '"Accept": "application/json"' in r
+        assert '"Content-Type": "application/json; charset=utf-8' in r
 
     def test_POST_explicit_JSON_auto_JSON_accept(self):
         r = http(
@@ -108,11 +110,11 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             'POST',
             httpbin('/post')
         )
-        self.assertIn(OK, r)
-        self.assertEqual(r.json['headers']['Accept'], 'application/json')
+        assert HTTP_OK in r
+        assert r.json['headers']['Accept'] == 'application/json'
         # Make sure Content-Type gets set even with no data.
         # https://github.com/jkbr/httpie/issues/137
-        self.assertIn('application/json', r.json['headers']['Content-Type'])
+        assert 'application/json' in r.json['headers']['Content-Type']
 
     def test_GET_explicit_JSON_explicit_headers(self):
         r = http(
@@ -122,9 +124,9 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             'Accept:application/xml',
             'Content-Type:application/xml'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Accept": "application/xml"', r)
-        self.assertIn('"Content-Type": "application/xml"', r)
+        assert HTTP_OK in r
+        assert '"Accept": "application/xml"' in r
+        assert '"Content-Type": "application/xml"' in r
 
     def test_POST_form_auto_Content_Type(self):
         r = http(
@@ -132,12 +134,8 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             'POST',
             httpbin('/post')
         )
-        self.assertIn(OK, r)
-        self.assertIn(
-            '"Content-Type":'
-            ' "application/x-www-form-urlencoded; charset=utf-8"',
-            r
-        )
+        assert HTTP_OK in r
+        assert '"Content-Type": "application/x-www-form-urlencoded' in r
 
     def test_POST_form_Content_Type_override(self):
         r = http(
@@ -146,8 +144,8 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
             httpbin('/post'),
             'Content-Type:application/xml'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"Content-Type": "application/xml"', r)
+        assert HTTP_OK in r
+        assert '"Content-Type": "application/xml"' in r
 
     def test_print_only_body_when_stdout_redirected_by_default(self):
 
@@ -159,7 +157,7 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
                 stdout_isatty=False
             )
         )
-        self.assertNotIn('HTTP/', r)
+        assert 'HTTP/' not in r
 
     def test_print_overridable_when_stdout_redirected(self):
 
@@ -172,4 +170,4 @@ class AutoContentTypeAndAcceptHeadersTest(BaseTestCase):
                 stdout_isatty=False
             )
         )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
diff --git a/tests/test_docs.py b/tests/test_docs.py
index 15731ff9..f19c4c5e 100644
--- a/tests/test_docs.py
+++ b/tests/test_docs.py
@@ -1,7 +1,8 @@
 import os
 import subprocess
+from unittest import TestCase
 
-from tests import TESTS_ROOT, BaseTestCase, skipIf
+from tests import TESTS_ROOT, skipIf
 
 
 def has_docutils():
@@ -25,9 +26,9 @@ def get_readme_errors():
         return err
 
 
-class READMETest(BaseTestCase):
+class READMETest(TestCase):
 
     @skipIf(not has_docutils(), 'docutils not installed')
     def test_README_reStructuredText_valid(self):
         errors = get_readme_errors()
-        self.assertFalse(errors, msg=errors)
+        assert not errors, errors
diff --git a/tests/test_downloads.py b/tests/test_downloads.py
index 93118c32..734872f2 100644
--- a/tests/test_downloads.py
+++ b/tests/test_downloads.py
@@ -1,5 +1,6 @@
 import os
 import time
+from unittest import TestCase
 
 from httpie.compat import urlopen
 from httpie.downloads import (
@@ -10,19 +11,17 @@ from httpie.downloads import (
     ContentRangeError,
     Download,
 )
-from tests import (
-    BaseTestCase, httpbin, http, TestEnvironment, Response
-)
+from tests import httpbin, http, TestEnvironment, Response
 
 
-class DownloadUtilsTest(BaseTestCase):
+class DownloadUtilsTest(TestCase):
 
     def test_Content_Range_parsing(self):
 
         parse = parse_content_range
 
-        self.assertEqual(parse('bytes 100-199/200', 100), 200)
-        self.assertEqual(parse('bytes 100-199/*', 100), 200)
+        assert parse('bytes 100-199/200', 100) == 200
+        assert parse('bytes 100-199/*', 100) == 200
 
         # missing
         self.assertRaises(ContentRangeError, parse, None, 100)
@@ -44,42 +43,34 @@ class DownloadUtilsTest(BaseTestCase):
 
     def test_Content_Disposition_parsing(self):
         parse = filename_from_content_disposition
-        self.assertEqual(
-            parse('attachment; filename=hello-WORLD_123.txt'),
-            'hello-WORLD_123.txt'
-        )
-        self.assertEqual(
-            parse('attachment; filename=".hello-WORLD_123.txt"'),
-            'hello-WORLD_123.txt'
-        )
-        self.assertEqual(
-            parse('attachment; filename="white space.txt"'),
-            'white space.txt'
-        )
-        self.assertEqual(
-            parse(r'attachment; filename="\"quotes\".txt"'),
-            '"quotes".txt'
-        )
-        self.assertEqual(parse('attachment; filename=/etc/hosts'), 'hosts')
-        self.assertIsNone(parse('attachment; filename='))
+        assert 'hello-WORLD_123.txt' == parse(
+            'attachment; filename=hello-WORLD_123.txt')
+        assert 'hello-WORLD_123.txt' == parse(
+            'attachment; filename=".hello-WORLD_123.txt"')
+        assert 'white space.txt' == parse(
+            'attachment; filename="white space.txt"')
+        assert '"quotes".txt' == parse(
+            r'attachment; filename="\"quotes\".txt"')
+        assert parse('attachment; filename=/etc/hosts') == 'hosts'
+        assert parse('attachment; filename=') is None
 
     def test_filename_from_url(self):
-        self.assertEqual(filename_from_url(
+        assert 'foo.txt' == filename_from_url(
             url='http://example.org/foo',
             content_type='text/plain'
-        ), 'foo.txt')
-        self.assertEqual(filename_from_url(
+        )
+        assert 'foo.html' == filename_from_url(
             url='http://example.org/foo',
             content_type='text/html; charset=utf8'
-        ), 'foo.html')
-        self.assertEqual(filename_from_url(
+        )
+        assert 'foo' == filename_from_url(
             url='http://example.org/foo',
             content_type=None
-        ), 'foo')
-        self.assertEqual(filename_from_url(
+        )
+        assert 'foo' == filename_from_url(
             url='http://example.org/foo',
             content_type='x-foo/bar'
-        ), 'foo')
+        )
 
     def test_unique_filename(self):
 
@@ -93,21 +84,12 @@ class DownloadUtilsTest(BaseTestCase):
             exists.attempt = 0
             return exists
 
-        self.assertEqual(
-            get_unique_filename('foo.bar', exists=make_exists()),
-            'foo.bar'
-        )
-        self.assertEqual(
-            get_unique_filename('foo.bar', exists=make_exists(1)),
-            'foo.bar-1'
-        )
-        self.assertEqual(
-            get_unique_filename('foo.bar', exists=make_exists(10)),
-            'foo.bar-10'
-        )
+        assert 'foo.bar' == get_unique_filename('foo.bar', make_exists())
+        assert 'foo.bar-1' == get_unique_filename('foo.bar', make_exists(1))
+        assert 'foo.bar-10' == get_unique_filename('foo.bar', make_exists(10))
 
 
-class DownloadsTest(BaseTestCase):
+class DownloadsTest(TestCase):
     # TODO: more tests
 
     def test_actual_download(self):
@@ -121,10 +103,10 @@ class DownloadsTest(BaseTestCase):
                 stdout_isatty=False
             )
         )
-        self.assertIn('Downloading', r.stderr)
-        self.assertIn('[K', r.stderr)
-        self.assertIn('Done', r.stderr)
-        self.assertEqual(body, r)
+        assert 'Downloading' in r.stderr
+        assert '[K' in r.stderr
+        assert 'Done' in r.stderr
+        assert body == r
 
     def test_download_with_Content_Length(self):
         download = Download(output_file=open(os.devnull, 'w'))
@@ -137,7 +119,7 @@ class DownloadsTest(BaseTestCase):
         time.sleep(1.1)
         download.chunk_downloaded(b'12345')
         download.finish()
-        self.assertFalse(download.interrupted)
+        assert not download.interrupted
 
     def test_download_no_Content_Length(self):
         download = Download(output_file=open(os.devnull, 'w'))
@@ -145,7 +127,7 @@ class DownloadsTest(BaseTestCase):
         time.sleep(1.1)
         download.chunk_downloaded(b'12345')
         download.finish()
-        self.assertFalse(download.interrupted)
+        assert not download.interrupted
 
     def test_download_interrupted(self):
         download = Download(output_file=open(os.devnull, 'w'))
@@ -155,4 +137,4 @@ class DownloadsTest(BaseTestCase):
         ))
         download.chunk_downloaded(b'1234')
         download.finish()
-        self.assertTrue(download.interrupted)
+        assert download.interrupted
diff --git a/tests/test_exit_status.py b/tests/test_exit_status.py
index c6e443b0..e2c02cba 100644
--- a/tests/test_exit_status.py
+++ b/tests/test_exit_status.py
@@ -1,30 +1,32 @@
+from unittest import TestCase
+
 import requests
 
 from httpie import ExitStatus
 from tests import (
-    BaseTestCase, TestEnvironment,
-    http, httpbin, OK, skip, skipIf
+    TestEnvironment,
+    http, httpbin, HTTP_OK, skip, skipIf
 )
 
 
-class ExitStatusTest(BaseTestCase):
+class ExitStatusTest(TestCase):
 
     def test_ok_response_exits_0(self):
         r = http(
             'GET',
             httpbin('/status/200')
         )
-        self.assertIn(OK, r)
-        self.assertEqual(r.exit_status, ExitStatus.OK)
+        assert HTTP_OK in r
+        assert r.exit_status == ExitStatus.OK
 
     def test_error_response_exits_0_without_check_status(self):
         r = http(
             'GET',
             httpbin('/status/500')
         )
-        self.assertIn('HTTP/1.1 500', r)
-        self.assertEqual(r.exit_status, ExitStatus.OK)
-        self.assertTrue(not r.stderr)
+        assert 'HTTP/1.1 500' in r
+        assert r.exit_status == ExitStatus.OK
+        assert not r.stderr
 
     @skip('timeout broken in requests'
           ' (https://github.com/jkbr/httpie/issues/185)')
@@ -34,7 +36,7 @@ class ExitStatusTest(BaseTestCase):
             'GET',
             httpbin('/delay/1')
         )
-        self.assertEqual(r.exit_status, ExitStatus.ERROR_TIMEOUT)
+        assert r.exit_status == ExitStatus.ERROR_TIMEOUT
 
     def test_3xx_check_status_exits_3_and_stderr_when_stdout_redirected(self):
         r = http(
@@ -44,9 +46,9 @@ class ExitStatusTest(BaseTestCase):
             httpbin('/status/301'),
             env=TestEnvironment(stdout_isatty=False,)
         )
-        self.assertIn('HTTP/1.1 301', r)
-        self.assertEqual(r.exit_status, ExitStatus.ERROR_HTTP_3XX)
-        self.assertIn('301 moved permanently', r.stderr.lower())
+        assert 'HTTP/1.1 301' in r
+        assert r.exit_status == ExitStatus.ERROR_HTTP_3XX
+        assert '301 moved permanently' in r.stderr.lower()
 
     @skipIf(requests.__version__ == '0.13.6',
             'Redirects with prefetch=False are broken in Requests 0.13.6')
@@ -58,8 +60,8 @@ class ExitStatusTest(BaseTestCase):
             httpbin('/status/301')
         )
         # The redirect will be followed so 200 is expected.
-        self.assertIn('HTTP/1.1 200 OK', r)
-        self.assertEqual(r.exit_status, ExitStatus.OK)
+        assert 'HTTP/1.1 200 OK' in r
+        assert r.exit_status == ExitStatus.OK
 
     def test_4xx_check_status_exits_4(self):
         r = http(
@@ -67,10 +69,10 @@ class ExitStatusTest(BaseTestCase):
             'GET',
             httpbin('/status/401')
         )
-        self.assertIn('HTTP/1.1 401', r)
-        self.assertEqual(r.exit_status, ExitStatus.ERROR_HTTP_4XX)
+        assert 'HTTP/1.1 401' in r
+        assert r.exit_status == ExitStatus.ERROR_HTTP_4XX
         # Also stderr should be empty since stdout isn't redirected.
-        self.assertTrue(not r.stderr)
+        assert not r.stderr
 
     def test_5xx_check_status_exits_5(self):
         r = http(
@@ -78,5 +80,5 @@ class ExitStatusTest(BaseTestCase):
             'GET',
             httpbin('/status/500')
         )
-        self.assertIn('HTTP/1.1 500', r)
-        self.assertEqual(r.exit_status, ExitStatus.ERROR_HTTP_5XX)
+        assert 'HTTP/1.1 500' in r
+        assert r.exit_status == ExitStatus.ERROR_HTTP_5XX
diff --git a/tests/test_httpie.py b/tests/test_httpie.py
index e2271488..d7ec971d 100644
--- a/tests/test_httpie.py
+++ b/tests/test_httpie.py
@@ -1,26 +1,28 @@
 """High-level tests."""
+from unittest import TestCase
+
 from tests import (
-    BaseTestCase, TestEnvironment,
-    http, httpbin, OK,
+    TestEnvironment,
+    http, httpbin, HTTP_OK,
     FILE_PATH, FILE_CONTENT
 )
 
 
-class HTTPieTest(BaseTestCase):
+class HTTPieTest(TestCase):
 
     def test_GET(self):
         r = http(
             'GET',
             httpbin('/get')
         )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
     def test_DELETE(self):
         r = http(
             'DELETE',
             httpbin('/delete')
         )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
     def test_PUT(self):
         r = http(
@@ -28,8 +30,8 @@ class HTTPieTest(BaseTestCase):
             httpbin('/put'),
             'foo=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn(r'\"foo\": \"bar\"', r)
+        assert HTTP_OK in r
+        assert r'\"foo\": \"bar\"' in r
 
     def test_POST_JSON_data(self):
         r = http(
@@ -37,8 +39,8 @@ class HTTPieTest(BaseTestCase):
             httpbin('/post'),
             'foo=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn(r'\"foo\": \"bar\"', r)
+        assert HTTP_OK in r
+        assert r'\"foo\": \"bar\"' in r
 
     def test_POST_form(self):
         r = http(
@@ -47,8 +49,8 @@ class HTTPieTest(BaseTestCase):
             httpbin('/post'),
             'foo=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"foo": "bar"', r)
+        assert HTTP_OK in r
+        assert '"foo": "bar"' in r
 
     def test_POST_form_multiple_values(self):
         r = http(
@@ -58,10 +60,8 @@ class HTTPieTest(BaseTestCase):
             'foo=bar',
             'foo=baz',
         )
-        self.assertIn(OK, r)
-        self.assertDictEqual(r.json['form'], {
-            'foo': ['bar', 'baz']
-        })
+        assert HTTP_OK in r
+        assert r.json['form'] == {'foo': ['bar', 'baz']}
 
     def test_POST_stdin(self):
 
@@ -77,8 +77,8 @@ class HTTPieTest(BaseTestCase):
                 httpbin('/post'),
                 env=env
             )
-        self.assertIn(OK, r)
-        self.assertIn(FILE_CONTENT, r)
+        assert HTTP_OK in r
+        assert FILE_CONTENT in r
 
     def test_headers(self):
         r = http(
@@ -86,6 +86,6 @@ class HTTPieTest(BaseTestCase):
             httpbin('/headers'),
             'Foo:bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"User-Agent": "HTTPie', r)
-        self.assertIn('"Foo": "bar"', r)
+        assert HTTP_OK in r
+        assert '"User-Agent": "HTTPie' in r
+        assert '"Foo": "bar"' in r
diff --git a/tests/test_output.py b/tests/test_output.py
index f59bf92d..d018e6f5 100644
--- a/tests/test_output.py
+++ b/tests/test_output.py
@@ -1,11 +1,14 @@
+from unittest import TestCase
+
+from httpie import ExitStatus
 from tests import (
-    BaseTestCase, TestEnvironment,
+    TestEnvironment,
     http, httpbin,
-    OK, COLOR, CRLF
+    HTTP_OK, COLOR, CRLF
 )
 
 
-class VerboseFlagTest(BaseTestCase):
+class VerboseFlagTest(TestCase):
 
     def test_verbose(self):
         r = http(
@@ -14,9 +17,8 @@ class VerboseFlagTest(BaseTestCase):
             httpbin('/get'),
             'test-header:__test__'
         )
-        self.assertIn(OK, r)
-        #noinspection PyUnresolvedReferences
-        self.assertEqual(r.count('__test__'), 2)
+        assert HTTP_OK in r
+        assert r.count('__test__') == 2
 
     def test_verbose_form(self):
         # https://github.com/jkbr/httpie/issues/53
@@ -28,8 +30,8 @@ class VerboseFlagTest(BaseTestCase):
             'foo=bar',
             'baz=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('foo=bar&baz=bar', r)
+        assert HTTP_OK in r
+        assert 'foo=bar&baz=bar' in r
 
     def test_verbose_json(self):
         r = http(
@@ -39,12 +41,12 @@ class VerboseFlagTest(BaseTestCase):
             'foo=bar',
             'baz=bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn('"baz": "bar"', r)  # request
-        self.assertIn(r'\"baz\": \"bar\"', r)  # response
+        assert HTTP_OK in r
+        assert '"baz": "bar"' in r  # request
+        assert r'\"baz\": \"bar\"' in r  # response
 
 
-class PrettyOptionsTest(BaseTestCase):
+class PrettyOptionsTest(TestCase):
     """Test the --pretty flag handling."""
 
     def test_pretty_enabled_by_default(self):
@@ -53,14 +55,14 @@ class PrettyOptionsTest(BaseTestCase):
             httpbin('/get'),
             env=TestEnvironment(colors=256),
         )
-        self.assertIn(COLOR, r)
+        assert COLOR in r
 
     def test_pretty_enabled_by_default_unless_stdout_redirected(self):
         r = http(
             'GET',
             httpbin('/get')
         )
-        self.assertNotIn(COLOR, r)
+        assert COLOR not in r
 
     def test_force_pretty(self):
         r = http(
@@ -69,7 +71,7 @@ class PrettyOptionsTest(BaseTestCase):
             httpbin('/get'),
             env=TestEnvironment(stdout_isatty=False, colors=256),
         )
-        self.assertIn(COLOR, r)
+        assert COLOR in r
 
     def test_force_ugly(self):
         r = http(
@@ -77,7 +79,7 @@ class PrettyOptionsTest(BaseTestCase):
             'GET',
             httpbin('/get'),
         )
-        self.assertNotIn(COLOR, r)
+        assert COLOR not in r
 
     def test_subtype_based_pygments_lexer_match(self):
         """Test that media subtype is used if type/subtype doesn't
@@ -92,7 +94,7 @@ class PrettyOptionsTest(BaseTestCase):
             'a=b',
             env=TestEnvironment(colors=256)
         )
-        self.assertIn(COLOR, r)
+        assert COLOR in r
 
     def test_colors_option(self):
         r = http(
@@ -105,8 +107,8 @@ class PrettyOptionsTest(BaseTestCase):
         )
         #noinspection PyUnresolvedReferences
         # Tests that the JSON data isn't formatted.
-        self.assertEqual(r.strip().count('\n'), 0)
-        self.assertIn(COLOR, r)
+        assert not r.strip().count('\n')
+        assert COLOR in r
 
     def test_format_option(self):
         r = http(
@@ -119,11 +121,11 @@ class PrettyOptionsTest(BaseTestCase):
         )
         #noinspection PyUnresolvedReferences
         # Tests that the JSON data is formatted.
-        self.assertEqual(r.strip().count('\n'), 2)
-        self.assertNotIn(COLOR, r)
+        assert r.strip().count('\n') == 2
+        assert COLOR not in r
 
 
-class LineEndingsTest(BaseTestCase):
+class LineEndingsTest(TestCase):
     """Test that CRLF is properly used in headers and
     as the headers/body separator."""
 
@@ -132,11 +134,11 @@ class LineEndingsTest(BaseTestCase):
         for header in lines:
             if header == CRLF:
                 break
-            self.assertTrue(header.endswith(CRLF), repr(header))
+            assert header.endswith(CRLF), repr(header)
         else:
             self.fail('CRLF between headers and body not found in %r' % msg)
         body = ''.join(lines)
-        self.assertNotIn(CRLF, body)
+        assert CRLF not in body
         return body
 
     def test_CRLF_headers_only(self):
@@ -146,7 +148,7 @@ class LineEndingsTest(BaseTestCase):
             httpbin('/get')
         )
         body = self._validate_crlf(r)
-        self.assertFalse(body, 'Garbage after headers: %r' % r)
+        assert not body, 'Garbage after headers: %r' % r
 
     def test_CRLF_ugly_response(self):
         r = http(
@@ -162,7 +164,7 @@ class LineEndingsTest(BaseTestCase):
             'GET',
             httpbin('/get')
         )
-        self.assertEqual(r.exit_status, 0)
+        assert r.exit_status == ExitStatus.OK
         self._validate_crlf(r)
 
     def test_CRLF_ugly_request(self):
diff --git a/tests/test_sessions.py b/tests/test_sessions.py
index f9ad3e5b..f47e831b 100644
--- a/tests/test_sessions.py
+++ b/tests/test_sessions.py
@@ -1,14 +1,15 @@
 import os
 import shutil
+from unittest import TestCase
 
 from tests import (
-    BaseTestCase, TestEnvironment,
+    TestEnvironment,
     mk_config_dir, http, httpbin,
-    OK,
+    HTTP_OK,
 )
 
 
-class SessionsTest(BaseTestCase):
+class SessionsTest(TestCase):
 
     @property
     def env(self):
@@ -27,7 +28,7 @@ class SessionsTest(BaseTestCase):
             'Hello:World',
             env=self.env
         )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
     def tearDown(self):
         shutil.rmtree(self.config_dir)
@@ -40,11 +41,10 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r)
-
-        self.assertEqual(r.json['headers']['Hello'], 'World')
-        self.assertEqual(r.json['headers']['Cookie'], 'hello=world')
-        self.assertIn('Basic ', r.json['headers']['Authorization'])
+        assert HTTP_OK in r
+        assert r.json['headers']['Hello'] == 'World'
+        assert r.json['headers']['Cookie'] == 'hello=world'
+        assert 'Basic ' in r.json['headers']['Authorization']
 
     def test_session_ignored_header_prefixes(self):
         r = http(
@@ -55,16 +55,16 @@ class SessionsTest(BaseTestCase):
             'If-Unmodified-Since: Sat, 29 Oct 1994 19:43:31 GMT',
             env=self.env
         )
-        self.assertIn(OK, r)
+        assert HTTP_OK in r
 
         r2 = http(
             '--session=test',
             'GET',
             httpbin('/get')
         )
-        self.assertIn(OK, r2)
-        self.assertNotIn('Content-Type', r2.json['headers'])
-        self.assertNotIn('If-Unmodified-Since', r2.json['headers'])
+        assert HTTP_OK in r2
+        assert 'Content-Type' not in r2.json['headers']
+        assert 'If-Unmodified-Since' not in r2.json['headers']
 
     def test_session_update(self):
         # Get a response to a request from the original session.
@@ -74,7 +74,7 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r1)
+        assert HTTP_OK in r1
 
         # Make a request modifying the session data.
         r2 = http(
@@ -86,7 +86,7 @@ class SessionsTest(BaseTestCase):
             'Hello:World2',
             env=self.env
         )
-        self.assertIn(OK, r2)
+        assert HTTP_OK in r2
 
         # Get a response to a request from the updated session.
         r3 = http(
@@ -95,12 +95,11 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r3)
-
-        self.assertEqual(r3.json['headers']['Hello'], 'World2')
-        self.assertEqual(r3.json['headers']['Cookie'], 'hello=world2')
-        self.assertNotEqual(r1.json['headers']['Authorization'],
-                            r3.json['headers']['Authorization'])
+        assert HTTP_OK in r3
+        assert r3.json['headers']['Hello'] == 'World2'
+        assert r3.json['headers']['Cookie'] == 'hello=world2'
+        assert (r1.json['headers']['Authorization'] !=
+                r3.json['headers']['Authorization'])
 
     def test_session_read_only(self):
         # Get a response from the original session.
@@ -110,7 +109,7 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r1)
+        assert HTTP_OK in r1
 
         # Make a request modifying the session data but
         # with --session-read-only.
@@ -123,7 +122,7 @@ class SessionsTest(BaseTestCase):
             'Hello:World2',
             env=self.env
         )
-        self.assertIn(OK, r2)
+        assert HTTP_OK in r2
 
         # Get a response from the updated session.
         r3 = http(
@@ -132,7 +131,7 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r3)
+        assert HTTP_OK in r3
 
         # Origin can differ on Travis.
         del r1.json['origin'], r3.json['origin']
@@ -140,11 +139,10 @@ class SessionsTest(BaseTestCase):
         del r1.json['headers']['X-Request-Id'], \
             r3.json['headers']['X-Request-Id']
         # Should be the same as before r2.
-        self.assertDictEqual(r1.json, r3.json)
+        assert r1.json == r3.json
 
     def test_session_by_path(self):
         session_path = os.path.join(self.config_dir, 'session-by-path.json')
-
         r1 = http(
             '--session=' + session_path,
             'GET',
@@ -152,7 +150,7 @@ class SessionsTest(BaseTestCase):
             'Foo:Bar',
             env=self.env
         )
-        self.assertIn(OK, r1)
+        assert HTTP_OK in r1
 
         r2 = http(
             '--session=' + session_path,
@@ -160,6 +158,6 @@ class SessionsTest(BaseTestCase):
             httpbin('/get'),
             env=self.env
         )
-        self.assertIn(OK, r2)
+        assert HTTP_OK in r2
 
-        self.assertEqual(r2.json['headers']['Foo'], 'Bar')
+        assert r2.json['headers']['Foo'] in 'Bar'
diff --git a/tests/test_stream.py b/tests/test_stream.py
index 48ce61c8..9e0664c0 100644
--- a/tests/test_stream.py
+++ b/tests/test_stream.py
@@ -1,13 +1,15 @@
+from unittest import TestCase
+
 from httpie.compat import is_windows
 from httpie.output import BINARY_SUPPRESSED_NOTICE
 from tests import (
     http, httpbin, skipIf,
-    BaseTestCase, TestEnvironment,
+    TestEnvironment,
     BIN_FILE_CONTENT, BIN_FILE_PATH
 )
 
 
-class StreamTest(BaseTestCase):
+class StreamTest(TestCase):
     # GET because httpbin 500s with binary POST body.
 
     @skipIf(is_windows, 'Pretty redirect not supported under Windows')
@@ -27,7 +29,7 @@ class StreamTest(BaseTestCase):
                     stdout_isatty=False,
                 )
             )
-        self.assertIn(BINARY_SUPPRESSED_NOTICE.decode(), r)
+        assert BINARY_SUPPRESSED_NOTICE.decode() in r
         # We get 'Bad Request' but it's okay.
         #self.assertIn(OK_COLOR, r)
 
@@ -46,7 +48,7 @@ class StreamTest(BaseTestCase):
                     stdin_isatty=False
                 ),
             )
-        self.assertIn(BINARY_SUPPRESSED_NOTICE.decode(), r)
+        assert BINARY_SUPPRESSED_NOTICE.decode() in r
         # We get 'Bad Request' but it's okay.
         #self.assertIn(OK, r)
 
@@ -68,4 +70,4 @@ class StreamTest(BaseTestCase):
             )
         # We get 'Bad Request' but it's okay.
         #self.assertIn(OK.encode(), r)
-        self.assertIn(BIN_FILE_CONTENT, r)
+        assert BIN_FILE_CONTENT in r
diff --git a/tests/test_uploads.py b/tests/test_uploads.py
index 932aa154..26627002 100644
--- a/tests/test_uploads.py
+++ b/tests/test_uploads.py
@@ -1,13 +1,14 @@
 import os
+from unittest import TestCase
 
 from httpie.input import ParseError
 from tests import (
-    BaseTestCase, TestEnvironment, http, httpbin,
-    FILE_PATH_ARG, FILE_PATH, OK, FILE_CONTENT,
+    TestEnvironment, http, httpbin,
+    FILE_PATH_ARG, FILE_PATH, HTTP_OK, FILE_CONTENT,
 )
 
 
-class MultipartFormDataFileUploadTest(BaseTestCase):
+class MultipartFormDataFileUploadTest(TestCase):
 
     def test_non_existent_file_raises_parse_error(self):
         self.assertRaises(ParseError, http,
@@ -27,16 +28,15 @@ class MultipartFormDataFileUploadTest(BaseTestCase):
             'foo=bar'
         )
 
-        self.assertIn(OK, r)
-        self.assertIn('Content-Disposition: form-data; name="foo"', r)
-        self.assertIn('Content-Disposition: form-data; name="test-file";'
-                      ' filename="%s"' % os.path.basename(FILE_PATH), r)
-        #noinspection PyUnresolvedReferences
-        self.assertEqual(r.count(FILE_CONTENT), 2)
-        self.assertIn('"foo": "bar"', r)
+        assert HTTP_OK in r
+        assert 'Content-Disposition: form-data; name="foo"' in r
+        assert 'Content-Disposition: form-data; name="test-file";' \
+               ' filename="%s"' % os.path.basename(FILE_PATH) in r
+        assert r.count(FILE_CONTENT) == 2
+        assert '"foo": "bar"' in r
 
 
-class RequestBodyFromFilePathTest(BaseTestCase):
+class RequestBodyFromFilePathTest(TestCase):
     """
     `http URL @file'
 
@@ -48,9 +48,9 @@ class RequestBodyFromFilePathTest(BaseTestCase):
             httpbin('/post'),
             '@' + FILE_PATH_ARG
         )
-        self.assertIn(OK, r)
-        self.assertIn(FILE_CONTENT, r)
-        self.assertIn('"Content-Type": "text/plain"', r)
+        assert HTTP_OK in r
+        assert FILE_CONTENT in r
+        assert '"Content-Type": "text/plain"' in r
 
     def test_request_body_from_file_by_path_with_explicit_content_type(self):
         r = http(
@@ -59,9 +59,9 @@ class RequestBodyFromFilePathTest(BaseTestCase):
             '@' + FILE_PATH_ARG,
             'Content-Type:x-foo/bar'
         )
-        self.assertIn(OK, r)
-        self.assertIn(FILE_CONTENT, r)
-        self.assertIn('"Content-Type": "x-foo/bar"', r)
+        assert HTTP_OK in r
+        assert FILE_CONTENT in r
+        assert '"Content-Type": "x-foo/bar"' in r
 
     def test_request_body_from_file_by_path_no_field_name_allowed(self):
         env = TestEnvironment(stdin_isatty=True)
@@ -71,7 +71,7 @@ class RequestBodyFromFilePathTest(BaseTestCase):
             'field-name@' + FILE_PATH_ARG,
             env=env
         )
-        self.assertIn('perhaps you meant --form?', r.stderr)
+        assert 'perhaps you meant --form?' in r.stderr
 
     def test_request_body_from_file_by_path_no_data_items_allowed(self):
         r = http(
@@ -81,4 +81,4 @@ class RequestBodyFromFilePathTest(BaseTestCase):
             'foo=bar',
             env=TestEnvironment(stdin_isatty=False)
         )
-        self.assertIn('cannot be mixed', r.stderr)
+        assert 'cannot be mixed' in r.stderr
diff --git a/tests/test_windows.py b/tests/test_windows.py
index caf1d87f..966d811f 100644
--- a/tests/test_windows.py
+++ b/tests/test_windows.py
@@ -1,13 +1,14 @@
 import os
 import tempfile
+from unittest import TestCase
 
 from tests import (
-    BaseTestCase, TestEnvironment,
+    TestEnvironment,
     http, httpbin, Environment, skip
 )
 
 
-class WindowsOnlyTests(BaseTestCase):
+class WindowsOnlyTests(TestCase):
 
     @skip('FIXME: kills the runner')
     #@skipIf(not is_windows, 'windows-only')
@@ -16,7 +17,7 @@ class WindowsOnlyTests(BaseTestCase):
         http(httpbin('/get'), env=Environment())
 
 
-class FakeWindowsTest(BaseTestCase):
+class FakeWindowsTest(TestCase):
 
     def test_output_file_pretty_not_allowed_on_windows(self):
 
@@ -28,5 +29,4 @@ class FakeWindowsTest(BaseTestCase):
             httpbin('/get'),
             env=TestEnvironment(is_windows=True)
         )
-        self.assertIn(
-            'Only terminal output can be colorized on Windows', r.stderr)
+        assert 'Only terminal output can be colorized on Windows' in r.stderr