diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index b8a0135043f..c5577aa9586 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -722,7 +722,7 @@ class MmapTests(unittest.TestCase):
         except SystemError:
             self.skipTest("resizing not supported")
         self.assertEqual(m.read(14), b'')
-        self.assertRaises(ValueError, m.read_byte,)
+        self.assertRaises(ValueError, m.read_byte)
         self.assertRaises(ValueError, m.write_byte, 42)
         self.assertRaises(ValueError, m.write, b'abc')