diff --git a/Lib/test/test_http_cookiejar.py b/Lib/test/test_http_cookiejar.py
index 712a4ae6398..41e0dfde330 100644
--- a/Lib/test/test_http_cookiejar.py
+++ b/Lib/test/test_http_cookiejar.py
@@ -257,7 +257,7 @@ class FileCookieJarTests(unittest.TestCase):
                                 "filename should not exist")
             except IOError as exc:
                 # exactly IOError, not LoadError
-                self.assertEqual(exc.__class__, IOError)
+                self.assertIs(exc.__class__, IOError)
             else:
                 self.fail("expected IOError for invalid filename")
         # Invalid contents of cookies file (eg. bad magic string)