diff --git a/Lib/test/test_unicodedata.py b/Lib/test/test_unicodedata.py
index 03ff058..95706b2 100644
--- a/Lib/test/test_unicodedata.py
+++ b/Lib/test/test_unicodedata.py
@@ -176,7 +176,7 @@
 
     def test_east_asian_width(self):
         eaw = self.db.east_asian_width
-        self.assertRaises(TypeError, eaw, 'a')
+        self.assertRaises(TypeError, eaw, str8('a'))
         self.assertRaises(TypeError, eaw, '')
         self.assertRaises(TypeError, eaw, 'ra')
         self.assertEqual(eaw('\x1e'), 'N')