diff --git a/Lib/test/test_tk.py b/Lib/test/test_tk.py
index dedda0d..3ece3d9 100644
--- a/Lib/test/test_tk.py
+++ b/Lib/test/test_tk.py
@@ -1,5 +1,6 @@
 import os
 import sys
+import unittest
 import Tkinter
 from test import test_support