1 files changed, 10 insertions, 1 deletions
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index 2593188..fa1727c 100644
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -2,10 +2,19 @@
 
 import unittest
 import os
+import _tkinter
 from test import support
 from tkinter import Tcl
 from _tkinter import TclError
 
+
+class TkinterTest(unittest.TestCase):
+
+    def testFlattenLen(self):
+        # flatten(<object with no length>)
+        self.assertRaises(TypeError, _tkinter._flatten, True)
+
+
 class TclTest(unittest.TestCase):
 
     def setUp(self):
@@ -151,7 +160,7 @@ class TclTest(unittest.TestCase):
                 os.environ['DISPLAY'] = old_display
 
 def test_main():
-    support.run_unittest(TclTest)
+    support.run_unittest(TclTest, TkinterTest)
 
 if __name__ == "__main__":
     test_main()