Fix a typo: TESTFN_UNENCODEABLE => TESTFN_UNENCODABLE
diff --git a/Lib/test/test_imp.py b/Lib/test/test_imp.py
index 233d3da..eb9eaef 100644
--- a/Lib/test/test_imp.py
+++ b/Lib/test/test_imp.py
@@ -307,10 +307,10 @@
 
 
 class NullImporterTests(unittest.TestCase):
-    @unittest.skipIf(support.TESTFN_UNENCODEABLE is None,
+    @unittest.skipIf(support.TESTFN_UNENCODABLE is None,
                      "Need an undecodeable filename")
     def test_unencodeable(self):
-        name = support.TESTFN_UNENCODEABLE
+        name = support.TESTFN_UNENCODABLE
         os.mkdir(name)
         try:
             self.assertRaises(ImportError, imp.NullImporter, name)