Index: Modules/posixmodule.c
===================================================================
--- Modules/posixmodule.c	(revision 66545)
+++ Modules/posixmodule.c	(working copy)
@@ -2323,10 +2323,10 @@
 #else
 
 	char *name = NULL;
-	PyObject *d, *v;
+	PyObject *d, *v, *warning;
 	DIR *dirp;
 	struct dirent *ep;
-	int arg_is_unicode = 1;
+	int arg_is_unicode = 1, ret;
 
 	errno = 0;
 	if (!PyArg_ParseTuple(args, "U:listdir", &v)) {
@@ -2378,9 +2378,21 @@
 				v = w;
 			}
 			else {
-				/* fall back to the original byte string, as
-				   discussed in patch #683592 */
 				PyErr_Clear();
+				warning = PyUnicode_FromFormat(
+					"Can't decode file name %R; ignoring",
+					v);
+				ret = PyErr_WarnEx(PyExc_UnicodeWarning,
+						   _PyUnicode_AsString(warning),
+						   2);
+				Py_DECREF(warning);
+				if (ret < 0) {
+					Py_DECREF(v);
+					Py_DECREF(d);
+					d = NULL;
+				        break;
+				}
+				continue;
 			}
 		}
 		if (PyList_Append(d, v) != 0) {