diff --git a/psutil/tests/test_aix.py b/psutil/tests/test_aix.py
index 6a5debfa2d..4a23b774ac 100755
--- a/psutil/tests/test_aix.py
+++ b/psutil/tests/test_aix.py
@@ -9,12 +9,12 @@
 """AIX specific tests."""
 
 import re
+import unittest
 
 import psutil
 from psutil import AIX
 from psutil.tests import PsutilTestCase
 from psutil.tests import sh
-from psutil.tests import unittest
 
 
 @unittest.skipIf(not AIX, "AIX only")
diff --git a/psutil/tests/test_bsd.py b/psutil/tests/test_bsd.py
index 1ae810f179..a236810dfc 100755
--- a/psutil/tests/test_bsd.py
+++ b/psutil/tests/test_bsd.py
@@ -14,6 +14,7 @@
 import os
 import re
 import time
+import unittest
 
 import psutil
 from psutil import BSD
@@ -27,7 +28,6 @@
 from psutil.tests import sh
 from psutil.tests import spawn_testproc
 from psutil.tests import terminate
-from psutil.tests import unittest
 from psutil.tests import which
 
 
diff --git a/psutil/tests/test_connections.py b/psutil/tests/test_connections.py
index 5381608a9b..f3b1f837ce 100755
--- a/psutil/tests/test_connections.py
+++ b/psutil/tests/test_connections.py
@@ -9,6 +9,7 @@
 import os
 import socket
 import textwrap
+import unittest
 from contextlib import closing
 from socket import AF_INET
 from socket import AF_INET6
@@ -39,7 +40,6 @@
 from psutil.tests import serialrun
 from psutil.tests import skip_on_access_denied
 from psutil.tests import tcp_socketpair
-from psutil.tests import unittest
 from psutil.tests import unix_socketpair
 from psutil.tests import wait_for_file
 
diff --git a/psutil/tests/test_contracts.py b/psutil/tests/test_contracts.py
index 9def408a90..5c927d68da 100755
--- a/psutil/tests/test_contracts.py
+++ b/psutil/tests/test_contracts.py
@@ -17,6 +17,7 @@
 import sys
 import time
 import traceback
+import unittest
 
 import psutil
 from psutil import AIX
@@ -51,7 +52,6 @@
 from psutil.tests import kernel_version
 from psutil.tests import process_namespace
 from psutil.tests import serialrun
-from psutil.tests import unittest
 
 
 # ===================================================================
diff --git a/psutil/tests/test_linux.py b/psutil/tests/test_linux.py
index 0d42d0515c..8dd4caaeaf 100755
--- a/psutil/tests/test_linux.py
+++ b/psutil/tests/test_linux.py
@@ -20,6 +20,7 @@
 import struct
 import textwrap
 import time
+import unittest
 import warnings
 
 import psutil
@@ -46,7 +47,6 @@
 from psutil.tests import safe_rmpath
 from psutil.tests import sh
 from psutil.tests import skip_on_not_implemented
-from psutil.tests import unittest
 from psutil.tests import which
 
 
diff --git a/psutil/tests/test_memleaks.py b/psutil/tests/test_memleaks.py
index d5baffa55f..e507e837c2 100755
--- a/psutil/tests/test_memleaks.py
+++ b/psutil/tests/test_memleaks.py
@@ -19,6 +19,7 @@
 
 import functools
 import os
+import unittest
 
 import psutil
 import psutil._common
@@ -50,7 +51,6 @@
 from psutil.tests import spawn_testproc
 from psutil.tests import system_namespace
 from psutil.tests import terminate
-from psutil.tests import unittest
 
 
 cext = psutil._psplatform.cext
diff --git a/psutil/tests/test_misc.py b/psutil/tests/test_misc.py
index aa30cbd6c0..add9646eb6 100755
--- a/psutil/tests/test_misc.py
+++ b/psutil/tests/test_misc.py
@@ -17,6 +17,7 @@
 import pickle
 import socket
 import stat
+import unittest
 
 import psutil
 import psutil.tests
@@ -51,7 +52,6 @@
 from psutil.tests import mock
 from psutil.tests import reload_module
 from psutil.tests import sh
-from psutil.tests import unittest
 
 
 # ===================================================================
diff --git a/psutil/tests/test_osx.py b/psutil/tests/test_osx.py
index 4f4b1c2906..d0f588ad6f 100755
--- a/psutil/tests/test_osx.py
+++ b/psutil/tests/test_osx.py
@@ -8,6 +8,7 @@
 
 import re
 import time
+import unittest
 
 import psutil
 from psutil import MACOS
@@ -20,7 +21,6 @@
 from psutil.tests import sh
 from psutil.tests import spawn_testproc
 from psutil.tests import terminate
-from psutil.tests import unittest
 
 
 if POSIX:
diff --git a/psutil/tests/test_posix.py b/psutil/tests/test_posix.py
index edef7e7d44..ebbf7a6e88 100755
--- a/psutil/tests/test_posix.py
+++ b/psutil/tests/test_posix.py
@@ -13,6 +13,7 @@
 import re
 import subprocess
 import time
+import unittest
 
 import psutil
 from psutil import AIX
@@ -32,7 +33,6 @@
 from psutil.tests import skip_on_access_denied
 from psutil.tests import spawn_testproc
 from psutil.tests import terminate
-from psutil.tests import unittest
 from psutil.tests import which
 
 
diff --git a/psutil/tests/test_process.py b/psutil/tests/test_process.py
index ef96e7971f..eb17e23939 100755
--- a/psutil/tests/test_process.py
+++ b/psutil/tests/test_process.py
@@ -19,6 +19,7 @@
 import textwrap
 import time
 import types
+import unittest
 
 import psutil
 from psutil import AIX
@@ -62,7 +63,6 @@
 from psutil.tests import sh
 from psutil.tests import skip_on_access_denied
 from psutil.tests import skip_on_not_implemented
-from psutil.tests import unittest
 from psutil.tests import wait_for_pid
 
 
diff --git a/psutil/tests/test_sunos.py b/psutil/tests/test_sunos.py
index ad94f774d6..dd74a49b0a 100755
--- a/psutil/tests/test_sunos.py
+++ b/psutil/tests/test_sunos.py
@@ -7,12 +7,12 @@
 """Sun OS specific tests."""
 
 import os
+import unittest
 
 import psutil
 from psutil import SUNOS
 from psutil.tests import PsutilTestCase
 from psutil.tests import sh
-from psutil.tests import unittest
 
 
 @unittest.skipIf(not SUNOS, "SUNOS only")
diff --git a/psutil/tests/test_system.py b/psutil/tests/test_system.py
index bb5edd5c3c..e130c935e1 100755
--- a/psutil/tests/test_system.py
+++ b/psutil/tests/test_system.py
@@ -16,6 +16,7 @@
 import socket
 import sys
 import time
+import unittest
 
 import psutil
 from psutil import AIX
@@ -50,7 +51,6 @@
 from psutil.tests import enum
 from psutil.tests import mock
 from psutil.tests import retry_on_failure
-from psutil.tests import unittest
 
 
 # ===================================================================
diff --git a/psutil/tests/test_testutils.py b/psutil/tests/test_testutils.py
index 89888dfe05..dd98538c0a 100755
--- a/psutil/tests/test_testutils.py
+++ b/psutil/tests/test_testutils.py
@@ -16,6 +16,7 @@
 import socket
 import stat
 import subprocess
+import unittest
 
 import psutil
 import psutil.tests
@@ -48,7 +49,6 @@
 from psutil.tests import system_namespace
 from psutil.tests import tcp_socketpair
 from psutil.tests import terminate
-from psutil.tests import unittest
 from psutil.tests import unix_socketpair
 from psutil.tests import wait_for_file
 from psutil.tests import wait_for_pid
diff --git a/psutil/tests/test_unicode.py b/psutil/tests/test_unicode.py
index e635726943..3fa3f0172a 100755
--- a/psutil/tests/test_unicode.py
+++ b/psutil/tests/test_unicode.py
@@ -76,6 +76,7 @@
 import os
 import shutil
 import traceback
+import unittest
 import warnings
 from contextlib import closing
 
@@ -108,7 +109,6 @@
 from psutil.tests import skip_on_access_denied
 from psutil.tests import spawn_testproc
 from psutil.tests import terminate
-from psutil.tests import unittest
 
 
 if APPVEYOR:
diff --git a/psutil/tests/test_windows.py b/psutil/tests/test_windows.py
index 0333dbe554..b89c67a961 100755
--- a/psutil/tests/test_windows.py
+++ b/psutil/tests/test_windows.py
@@ -17,6 +17,7 @@
 import subprocess
 import sys
 import time
+import unittest
 import warnings
 
 import psutil
@@ -36,7 +37,6 @@
 from psutil.tests import sh
 from psutil.tests import spawn_testproc
 from psutil.tests import terminate
-from psutil.tests import unittest
 
 
 if WINDOWS and not PYPY: