diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index 53a3ddb..d5a9a29 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -1154,7 +1154,7 @@
             s2 = "".join([s1])
             self.assert_(s1 is s2)
 
-        elif t is str:
+        elif t is str8:
             s1 = subclass("abcd")
             s2 = "".join([s1])
             self.assert_(s1 is not s2)
diff --git a/Lib/test/test_str.py b/Lib/test/test_str.py
index be26b24..6fa3779 100644
--- a/Lib/test/test_str.py
+++ b/Lib/test/test_str.py
@@ -9,7 +9,7 @@
     string_tests.MixinStrUnicodeTest,
     ):
 
-    type2test = str
+    type2test = str8
 
     # We don't need to propagate to str
     def fixtype(self, obj):