Index: Lib/test/test_zlib.py
===================================================================
--- Lib/test/test_zlib.py	(révision 66240)
+++ Lib/test/test_zlib.py	(copie de travail)
@@ -110,6 +110,8 @@
         y1 = dco.decompress(x1 + x2)
         y2 = dco.flush()
         self.assertEqual(data, y1 + y2)
+        self.assert_(isinstance(dco.unconsumed_tail, bytes))
+        self.assert_(isinstance(dco.unused_data, bytes))
 
     def test_compressoptions(self):
         # specify lots of options to compressobj()
Index: Modules/zlibmodule.c
===================================================================
--- Modules/zlibmodule.c	(révision 66240)
+++ Modules/zlibmodule.c	(copie de travail)
@@ -96,12 +96,12 @@
     if (self == NULL)
 	return NULL;
     self->is_initialised = 0;
-    self->unused_data = PyByteArray_FromStringAndSize("", 0);
+    self->unused_data = PyBytes_FromStringAndSize("", 0);
     if (self->unused_data == NULL) {
 	Py_DECREF(self);
 	return NULL;
     }
-    self->unconsumed_tail = PyByteArray_FromStringAndSize("", 0);
+    self->unconsumed_tail = PyBytes_FromStringAndSize("", 0);
     if (self->unconsumed_tail == NULL) {
 	Py_DECREF(self);
 	return NULL;
@@ -560,7 +560,7 @@
        of specified size. Return the unconsumed tail in an attribute.*/
     if(max_length) {
 	Py_DECREF(self->unconsumed_tail);
-	self->unconsumed_tail = PyByteArray_FromStringAndSize((char *)self->zst.next_in,
+	self->unconsumed_tail = PyBytes_FromStringAndSize((char *)self->zst.next_in,
 							   self->zst.avail_in);
 	if(!self->unconsumed_tail) {
 	    Py_DECREF(RetVal);
@@ -577,7 +577,7 @@
     */
     if (err == Z_STREAM_END) {
 	Py_XDECREF(self->unused_data);  /* Free original empty string */
-	self->unused_data = PyByteArray_FromStringAndSize(
+	self->unused_data = PyBytes_FromStringAndSize(
 	    (char *)self->zst.next_in, self->zst.avail_in);
 	if (self->unused_data == NULL) {
 	    Py_DECREF(RetVal);