diff --git a/tests/test_parser.py b/tests/test_parser.py
index 1c46f66..cf75262 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -65,8 +65,8 @@ class ParserTestCase(unittest.TestCase):
         e = list(token_generator(''))
         self.assertEqual(len(e), 2)
         self.assertEqual(e[0].prev, None)
-        self.assertIsInstance(e[0].curr, yaml.Token)
-        self.assertIsInstance(e[0].next, yaml.Token)
+        self.assertTrue(isinstance(e[0].curr, yaml.Token))
+        self.assertTrue(isinstance(e[0].next, yaml.Token))
         self.assertEqual(e[1].prev, e[0].curr)
         self.assertEqual(e[1].curr, e[0].next)
         self.assertEqual(e[1].next, None)
@@ -74,20 +74,20 @@ class ParserTestCase(unittest.TestCase):
         e = list(token_generator('---\n'
                                  'k: v\n'))
         self.assertEqual(len(e), 9)
-        self.assertIsInstance(e[3].curr, yaml.KeyToken)
-        self.assertIsInstance(e[5].curr, yaml.ValueToken)
+        self.assertTrue(isinstance(e[3].curr, yaml.KeyToken))
+        self.assertTrue(isinstance(e[5].curr, yaml.ValueToken))
 
     def test_token_or_line_generator(self):
         e = list(token_or_line_generator('---\n'
                                          'k: v\n'))
         self.assertEqual(len(e), 12)
-        self.assertIsInstance(e[0], Token)
-        self.assertIsInstance(e[0].curr, yaml.StreamStartToken)
-        self.assertIsInstance(e[1], Token)
-        self.assertIsInstance(e[1].curr, yaml.DocumentStartToken)
-        self.assertIsInstance(e[2], Line)
-        self.assertIsInstance(e[3].curr, yaml.BlockMappingStartToken)
-        self.assertIsInstance(e[4].curr, yaml.KeyToken)
-        self.assertIsInstance(e[6].curr, yaml.ValueToken)
-        self.assertIsInstance(e[8], Line)
-        self.assertIsInstance(e[11], Line)
+        self.assertTrue(isinstance(e[0], Token))
+        self.assertTrue(isinstance(e[0].curr, yaml.StreamStartToken))
+        self.assertTrue(isinstance(e[1], Token))
+        self.assertTrue(isinstance(e[1].curr, yaml.DocumentStartToken))
+        self.assertTrue(isinstance(e[2], Line))
+        self.assertTrue(isinstance(e[3].curr, yaml.BlockMappingStartToken))
+        self.assertTrue(isinstance(e[4].curr, yaml.KeyToken))
+        self.assertTrue(isinstance(e[6].curr, yaml.ValueToken))
+        self.assertTrue(isinstance(e[8], Line))
+        self.assertTrue(isinstance(e[11], Line))