diff -r 253c31930b32 Lib/test/test_io.py
--- a/Lib/test/test_io.py	Sat Jul 26 00:58:55 2014 +0200
+++ b/Lib/test/test_io.py	Sat Jul 26 12:49:05 2014 +0200
@@ -1189,6 +1189,13 @@
         with self.assertRaisesRegex(TypeError, "BufferedReader"):
             self.tp(io.BytesIO(), 1024, 1024, 1024)
 
+    def test_resource_warning(self):
+        with support.check_warnings(('', ResourceWarning)):
+            stream = open(support.TESTFN, 'r')
+            self.addCleanup(stream.close)
+            bufio = self.tp(stream)
+            del bufio
+            support.gc_collect()
 
 class PyBufferedReaderTest(BufferedReaderTest):
     tp = pyio.BufferedReader
@@ -1497,6 +1504,14 @@
         with self.assertRaisesRegex(TypeError, "BufferedWriter"):
             self.tp(io.BytesIO(), 1024, 1024, 1024)
 
+    def test_resource_warning(self):
+        with support.check_warnings(('', ResourceWarning)):
+            stream = open(support.TESTFN, 'w')
+            self.addCleanup(stream.close)
+            bufio = self.tp(stream)
+            del bufio
+            support.gc_collect()
+
 
 class PyBufferedWriterTest(BufferedWriterTest):
     tp = pyio.BufferedWriter
diff -r 253c31930b32 Modules/_io/textio.c
--- a/Modules/_io/textio.c	Sat Jul 26 00:58:55 2014 +0200
+++ b/Modules/_io/textio.c	Sat Jul 26 12:49:05 2014 +0200
@@ -1160,6 +1160,18 @@
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
 
+static PyObject*
+textiowrapper_dealloc_warn(textio *self, PyObject *source)
+{
+    PyObject* res;
+    res = _PyObject_CallMethodId(self->buffer, &PyId__dealloc_warn, "O", self);
+    if (res)
+       Py_DECREF(res);
+    else
+       PyErr_Clear();
+    Py_RETURN_NONE;
+}
+
 static int
 textiowrapper_traverse(textio *self, visitproc visit, void *arg)
 {
@@ -2754,6 +2766,7 @@
     {"seek", (PyCFunction)textiowrapper_seek, METH_VARARGS},
     {"tell", (PyCFunction)textiowrapper_tell, METH_NOARGS},
     {"truncate", (PyCFunction)textiowrapper_truncate, METH_VARARGS},
+    {"_dealloc_warn", (PyCFunction)textiowrapper_dealloc_warn, METH_O, NULL},
     {NULL, NULL}
 };