diff --git a/Include/fileobject.h b/Include/fileobject.h
index 40d871aea5d..0f40089ef19 100644
--- a/Include/fileobject.h
+++ b/Include/fileobject.h
@@ -20,6 +20,7 @@ PyAPI_FUNC(char *) Py_UniversalNewlineFgets(char *, int, FILE*, PyObject *);
    If non-NULL, this is different than the default encoding for strings
 */
 PyAPI_DATA(const char *) Py_FileSystemDefaultEncoding;
+PyAPI_DATA(const int) Py_HasFileSystemDefaultEncoding;
 
 /* Internal API
 
diff --git a/Objects/object.c b/Objects/object.c
index df93a192d60..64146736404 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1532,8 +1532,15 @@ _Py_ForgetReference(register PyObject *op)
 	if (op->ob_refcnt < 0)
 		Py_FatalError("UNREF negative refcnt");
 	if (op == &refchain ||
-	    op->_ob_prev->_ob_next != op || op->_ob_next->_ob_prev != op)
+	    op->_ob_prev->_ob_next != op || op->_ob_next->_ob_prev != op) {
+		fprintf(stderr, "* ob\n");
+		_PyObject_Dump(op);
+		fprintf(stderr, "* op->_ob_prev->_ob_next\n");
+		_PyObject_Dump(op->_ob_prev->_ob_next);
+		fprintf(stderr, "* op->_ob_next->_ob_prev\n");
+		_PyObject_Dump(op->_ob_next->_ob_prev);
 		Py_FatalError("UNREF invalid object");
+	}
 #ifdef SLOW_UNREF_CHECK
 	for (p = refchain._ob_next; p != &refchain; p = p->_ob_next) {
 		if (p == op)
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index b109ba7c3b8..fb7e223367e 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -16,10 +16,13 @@
 */
 #if defined(MS_WINDOWS) && defined(HAVE_USABLE_WCHAR_T)
 const char *Py_FileSystemDefaultEncoding = "mbcs";
+const int Py_HasFileSystemDefaultEncoding = 1;
 #elif defined(__APPLE__)
 const char *Py_FileSystemDefaultEncoding = "utf-8";
+const int Py_HasFileSystemDefaultEncoding = 1;
 #else
 const char *Py_FileSystemDefaultEncoding = NULL; /* use default */
+const int Py_HasFileSystemDefaultEncoding = 0;
 #endif
 
 static PyObject *
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 0ba8646ab5d..5766b2385e5 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -502,6 +502,12 @@ Py_Finalize(void)
 	/* Cleanup Unicode implementation */
 	_PyUnicode_Fini();
 
+	/* reset file system default encoding */
+	if (!Py_HasFileSystemDefaultEncoding) {
+		free((char*)Py_FileSystemDefaultEncoding);
+        	Py_FileSystemDefaultEncoding = NULL;
+	}
+
 	/* XXX Still allocated:
 	   - various static ad-hoc pointers to interned strings
 	   - int and float free list blocks