diff --git a/tests/_test_tokenizer.py b/tests/_test_tokenizer.py
index 13882aa..379b4fa 100644
--- a/tests/_test_tokenizer.py
+++ b/tests/_test_tokenizer.py
@@ -21,7 +21,6 @@
 # SOFTWARE.
 
 from __future__ import print_function, unicode_literals
-from unittest import TestCase
 from os import listdir, path
 
 from mwparserfromhell.compat import py3k
@@ -32,7 +31,7 @@ class _TestParseError(Exception):
     pass
 
 
-class TokenizerTestCase(TestCase):
+class TokenizerTestCase(object):
     """A base test case for tokenizers, whose tests are loaded dynamically.
 
     Subclassed along with unittest.TestCase to form TestPyTokenizer and
diff --git a/tests/test_ctokenizer.py b/tests/test_ctokenizer.py
index 955b9a0..7a082e8 100644
--- a/tests/test_ctokenizer.py
+++ b/tests/test_ctokenizer.py
@@ -31,7 +31,7 @@ except ImportError:
 from ._test_tokenizer import TokenizerTestCase
 
 @unittest.skipUnless(CTokenizer, "C tokenizer not available")
-class TestCTokenizer(TokenizerTestCase):
+class TestCTokenizer(TokenizerTestCase, unittest.TestCase):
     """Test cases for the C tokenizer."""
 
     @classmethod
diff --git a/tests/test_pytokenizer.py b/tests/test_pytokenizer.py
index 7b37eb3..697c7e5 100644
--- a/tests/test_pytokenizer.py
+++ b/tests/test_pytokenizer.py
@@ -27,7 +27,7 @@ from mwparserfromhell.parser.tokenizer import Tokenizer
 
 from ._test_tokenizer import TokenizerTestCase
 
-class TestPyTokenizer(TokenizerTestCase):
+class TestPyTokenizer(TokenizerTestCase, unittest.TestCase):
     """Test cases for the Python tokenizer."""
 
     @classmethod