Index: Modules/posixmodule.c
===================================================================
--- Modules/posixmodule.c	(revision 66633)
+++ Modules/posixmodule.c	(working copy)
@@ -2326,14 +2326,16 @@
 	PyObject *d, *v;
 	DIR *dirp;
 	struct dirent *ep;
-	int arg_is_unicode = 1;
+	int arg_is_unicode = 1, force_unicode = 1;
 
 	errno = 0;
-	if (!PyArg_ParseTuple(args, "U:listdir", &v)) {
+	if (!PyArg_ParseTuple(args, "U|i:listdir", &v, &force_unicode)) {
 		arg_is_unicode = 0;
+		force_unicode = 0;
 		PyErr_Clear();
 	}
-	if (!PyArg_ParseTuple(args, "et:listdir", Py_FileSystemDefaultEncoding, &name))
+	if (!PyArg_ParseTuple(args, "et|i:listdir", Py_FileSystemDefaultEncoding, &name,
+			      &force_unicode))
 		return NULL;
 	if ((dirp = opendir(name)) == NULL) {
 		return posix_error_with_allocated_filename(name);
@@ -2367,7 +2369,7 @@
 			d = NULL;
 			break;
 		}
-		if (arg_is_unicode) {
+		if (arg_is_unicode || force_unicode) {
 			PyObject *w;
 
 			w = PyUnicode_FromEncodedObject(v,
@@ -2377,11 +2379,16 @@
 				Py_DECREF(v);
 				v = w;
 			}
-			else {
-				/* fall back to the original byte string, as
-				   discussed in patch #683592 */
+			else if (!force_unicode &&
+				 PyErr_ExceptionMatches(PyExc_UnicodeDecodeError)) {
 				PyErr_Clear();
 			}
+			else {
+				Py_DECREF(v);
+				Py_DECREF(d);
+				d = NULL;
+				break;
+			}
 		}
 		if (PyList_Append(d, v) != 0) {
 			Py_DECREF(v);