Index: Lib/test/test_datetime.py
===================================================================
--- Lib/test/test_datetime.py	(revision 82614)
+++ Lib/test/test_datetime.py	(working copy)
@@ -161,7 +161,9 @@
 
 
     def test_constructor(self):
-        self.assertEqual(timezone.utc, timezone(timedelta(0)))
+        self.assertIs(timezone.utc, timezone(timedelta(0)))
+        self.assertIsNot(timezone.utc, timezone(timedelta(0), 'UTC'))
+        self.assertEqual(timezone.utc, timezone(timedelta(0), 'UTC'))
         # invalid offsets
         for invalid in [timedelta(microseconds=1), timedelta(1, 1),
                         timedelta(seconds=1), timedelta(1), -timedelta(1)]:
Index: Modules/datetimemodule.c
===================================================================
--- Modules/datetimemodule.c	(revision 82614)
+++ Modules/datetimemodule.c	(working copy)
@@ -780,12 +780,15 @@
     PyObject *name;
 } PyDateTime_TimeZone;
 
+/* The interned UTC timezone instance */ 
+static PyObject *PyDateTime_TimeZone_UTC;
+
 /* Create new timezone instance checking offset range.  This
    function does not check the name argument.  Caller must assure
    that offset is a timedelta instance and name is either NULL
    or a unicode object. */
 static PyObject *
-new_timezone(PyObject *offset, PyObject *name)
+create_timezone(PyObject *offset, PyObject *name)
 {
     PyDateTime_TimeZone *self;
     PyTypeObject *type = &PyDateTime_TimeZoneType;
@@ -818,6 +821,22 @@
     return (PyObject *)self;
 }
 
+static int delta_bool(PyDateTime_Delta *self);
+
+static PyObject *
+new_timezone(PyObject *offset, PyObject *name)
+{
+    assert(offset != NULL);
+    assert(PyDelta_Check(offset));
+    assert(name == NULL || PyUnicode_Check(name));
+
+    if (name == NULL && delta_bool((PyDateTime_Delta *)offset) == 0) {
+        Py_INCREF(PyDateTime_TimeZone_UTC);
+        return PyDateTime_TimeZone_UTC;
+    }
+    return create_timezone(offset, name);
+}
+
 /* ---------------------------------------------------------------------------
  * tzinfo helpers.
  */
@@ -5256,11 +5275,11 @@
     delta = new_delta(0, 0, 0, 0);
     if (delta == NULL)
         return NULL;
-    x = new_timezone(delta, NULL);
+    x = create_timezone(delta, NULL);
     Py_DECREF(delta);
     if (x == NULL || PyDict_SetItemString(d, "utc", x) < 0)
         return NULL;
-    Py_DECREF(x);
+    PyDateTime_TimeZone_UTC = x;
 
     delta = new_delta(-1, 60, 0, 1); /* -23:59 */
     if (delta == NULL)