Index: src/org/python/core/PyString.java
===================================================================
--- src/org/python/core/PyString.java	(revision 3416)
+++ src/org/python/core/PyString.java	(working copy)
@@ -1583,7 +1583,7 @@
             if(S == null) {
                 return new PyString("");
             }
-            return S.__str__();
+            return new PyString(S.__str__().toString());
         } else {
             if (S == null) {
                 return new PyStringDerived(subtype, "");
Index: Lib/test/test_subclasses.py
===================================================================
--- Lib/test/test_subclasses.py	(revision 3416)
+++ Lib/test/test_subclasses.py	(working copy)
@@ -190,10 +190,6 @@
 
 
 def test_main():
-# Jython transition 2.3
-# pickle fails on subclasses of builtin types
-# http://jython.org/bugs/1768990
-    del TestSubclasses.test_pickle_builtins
     test_support.run_unittest(TestSubclasses)
 
 if __name__ == "__main__":