diff -r 6bcedf96d25f Lib/test/test_dict.py
--- a/Lib/test/test_dict.py	Tue Sep 13 20:48:25 2016 +0200
+++ b/Lib/test/test_dict.py	Wed Sep 14 16:57:54 2016 +0800
@@ -916,6 +916,34 @@
         self.assertEqual(list(a), ['x', 'y'])
         self.assertEqual(list(b), ['x', 'y', 'z'])
 
+    @support.cpython_only
+    def test_capi_getitem_knownhash(self):
+        from _testcapi import dict_getitem_knownhash, error
+
+        d = {'x': 1, 'y': 2, 'z': 3}
+        self.assertEqual(dict_getitem_knownhash(d, 'x', hash('x')), 1)
+        self.assertEqual(dict_getitem_knownhash(d, 'y', hash('y')), 2)
+        self.assertEqual(dict_getitem_knownhash(d, 'z', hash('z')), 3)
+
+        # dict_getitem_knownhash needs 3 arguments
+        self.assertRaises(TypeError, dict_getitem_knownhash)
+        # not a dict
+        self.assertRaises(error, dict_getitem_knownhash, [], 1, hash(1))
+        # key does not exist
+        self.assertRaises(error, dict_getitem_knownhash, {}, 1, hash(1))
+
+        class Exc(Exception): pass
+        class BadEq:
+            def __eq__(self, other):
+                raise Exc
+            def __hash__(self):
+                return 7
+
+        k1, k2 = BadEq(), BadEq()
+        d = {k1: 1}
+        self.assertEqual(dict_getitem_knownhash(d, k1, hash(k1)), 1)
+        self.assertRaises(error, dict_getitem_knownhash, d, k2, hash(k2))
+
     def test_iterator_pickling(self):
         for proto in range(pickle.HIGHEST_PROTOCOL + 1):
             data = {1:"a", 2:"b", 3:"c"}
diff -r 6bcedf96d25f Modules/_testcapimodule.c
--- a/Modules/_testcapimodule.c	Tue Sep 13 20:48:25 2016 +0200
+++ b/Modules/_testcapimodule.c	Wed Sep 14 16:57:54 2016 +0800
@@ -238,6 +238,28 @@
     return Py_None;
 }
 
+static PyObject*
+dict_getitem_knownhash(PyObject *self, PyObject *args)
+{
+    PyObject *mp, *key, *result;
+    Py_hash_t hash;
+
+    if (!PyArg_ParseTuple(args, "OOn:dict_get_item_knownhash",
+                          &mp, &key, &hash)) {
+        return NULL;
+    }
+
+    PyErr_Clear();
+    result = _PyDict_GetItem_KnownHash(mp, key, hash);  // borrowed reference
+    if (result == NULL && !PyErr_Occurred()) {
+        PyErr_SetString(TestError, "dict_getitem_knownhash: the key "
+                        "does not exist or an unexcepted error happened");
+    }
+
+    Py_XINCREF(result);
+    return result;
+}
+
 
 /* Issue #4701: Check that PyObject_Hash implicitly calls
  *   PyType_Ready if it hasn't already been called
@@ -3940,6 +3962,7 @@
     {"test_datetime_capi",  test_datetime_capi,              METH_NOARGS},
     {"test_list_api",           (PyCFunction)test_list_api,      METH_NOARGS},
     {"test_dict_iteration",     (PyCFunction)test_dict_iteration,METH_NOARGS},
+    {"dict_getitem_knownhash",  dict_getitem_knownhash,          METH_VARARGS},
     {"test_lazy_hash_inheritance",      (PyCFunction)test_lazy_hash_inheritance,METH_NOARGS},
     {"test_long_api",           (PyCFunction)test_long_api,      METH_NOARGS},
     {"test_xincref_doesnt_leak",(PyCFunction)test_xincref_doesnt_leak,      METH_NOARGS},
diff -r 6bcedf96d25f Objects/dictobject.c
--- a/Objects/dictobject.c	Tue Sep 13 20:48:25 2016 +0200
+++ b/Objects/dictobject.c	Wed Sep 14 16:57:54 2016 +0800
@@ -649,8 +649,10 @@
             Py_INCREF(startkey);
             cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
             Py_DECREF(startkey);
-            if (cmp < 0)
+            if (cmp < 0) {
+                *value_addr = NULL;
                 return DKIX_ERROR;
+            }
             if (dk == mp->ma_keys && ep->me_key == startkey) {
                 if (cmp > 0) {
                     *value_addr = &ep->me_value;
@@ -1366,12 +1368,12 @@
         ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &value_addr, NULL);
         /* ignore errors */
         PyErr_Restore(err_type, err_value, err_tb);
-        if (ix == DKIX_EMPTY)
+        if (ix < 0)
             return NULL;
     }
     else {
         ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &value_addr, NULL);
-        if (ix == DKIX_EMPTY) {
+        if (ix < 0) {
             PyErr_Clear();
             return NULL;
         }