diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 3f22e7c..ab6207b 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -2784,6 +2784,17 @@
 	return NULL;
 }
 
+PyDoc_STRVAR(sizeof__doc__,
+"S.__sizeof__() -> size of S in memory, in bytes");
+
+static PyObject *
+string_sizeof(PyBytesObject *v)
+{
+	Py_ssize_t res;
+	res = sizeof(PyBytesObject) + Py_SIZE(v) * Py_TYPE(v)->tp_itemsize;
+	return PyLong_FromSsize_t(res);
+}
+
 
 static PyObject *
 string_getnewargs(PyBytesObject *v)
@@ -2848,6 +2859,8 @@
 	 translate__doc__},
 	{"upper", (PyCFunction)stringlib_upper, METH_NOARGS, _Py_upper__doc__},
 	{"zfill", (PyCFunction)stringlib_zfill, METH_VARARGS, zfill__doc__},
+	{"__sizeof__", (PyCFunction)string_sizeof, METH_NOARGS,
+	 sizeof__doc__},
 	{NULL,     NULL}		     /* sentinel */
 };
 
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index fc2c8f0..b4f9182 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -1840,11 +1840,28 @@
 
 static PyObject *dictiter_new(PyDictObject *, PyTypeObject *);
 
+static PyObject *
+dict_sizeof(PyDictObject *mp)
+{
+	Py_ssize_t res;
+
+	res = sizeof(PyDictObject) + sizeof(mp->ma_table);
+	if (mp->ma_table != mp->ma_smalltable)
+		res = res + (mp->ma_mask + 1) * sizeof(PyDictEntry);
+	return PyLong_FromSsize_t(res);
+}
+
+PyDoc_STRVAR(has_key__doc__,
+"D.has_key(k) -> True if D has a key k, else False");
+
 PyDoc_STRVAR(contains__doc__,
 "D.__contains__(k) -> True if D has a key k, else False");
 
 PyDoc_STRVAR(getitem__doc__, "x.__getitem__(y) <==> x[y]");
 
+PyDoc_STRVAR(sizeof__doc__,
+"D.__sizeof__() -> size of D in memory, in bytes");
+
 PyDoc_STRVAR(get__doc__,
 "D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None.");
 
@@ -1890,6 +1907,8 @@
 	 contains__doc__},
 	{"__getitem__", (PyCFunction)dict_subscript,	METH_O | METH_COEXIST,
 	 getitem__doc__},
+	{"__sizeof__",	(PyCFunction)dict_sizeof,	METH_NOARGS,
+	 sizeof__doc__},
 	{"get",         (PyCFunction)dict_get,          METH_VARARGS,
 	 get__doc__},
 	{"setdefault",  (PyCFunction)dict_setdefault,   METH_VARARGS,
diff --git a/Objects/listobject.c b/Objects/listobject.c
index c84cce5..d5f3a19 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2247,6 +2247,15 @@
 	return 0;
 }
 
+static PyObject *
+list_sizeof(PyListObject *self)
+{
+	Py_ssize_t res;
+
+	res = sizeof(PyListObject) + self->allocated * sizeof(void*);
+	return PyLong_FromSsize_t(res);
+}
+
 static PyObject *list_iter(PyObject *seq);
 static PyObject *list_reversed(PyListObject* seq, PyObject* unused);
 
@@ -2254,6 +2263,8 @@
 "x.__getitem__(y) <==> x[y]");
 PyDoc_STRVAR(reversed_doc,
 "L.__reversed__() -- return a reverse iterator over the list");
+PyDoc_STRVAR(sizeof_doc,
+"L.__sizeof__() -- size of L in memory, in bytes");
 PyDoc_STRVAR(append_doc,
 "L.append(object) -- append object to end");
 PyDoc_STRVAR(extend_doc,
@@ -2279,6 +2290,7 @@
 static PyMethodDef list_methods[] = {
 	{"__getitem__", (PyCFunction)list_subscript, METH_O|METH_COEXIST, getitem_doc},
 	{"__reversed__",(PyCFunction)list_reversed, METH_NOARGS, reversed_doc},
+	{"__sizeof__",  (PyCFunction)list_sizeof, METH_NOARGS, sizeof_doc},
 	{"append",	(PyCFunction)listappend,  METH_O, append_doc},
 	{"insert",	(PyCFunction)listinsert,  METH_VARARGS, insert_doc},
 	{"extend",      (PyCFunction)listextend,  METH_O, extend_doc},
diff --git a/Objects/longobject.c b/Objects/longobject.c
index 10d03ae..d0d4d3a 100644
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -3625,6 +3625,17 @@
 #undef UNDEF_NDIGITS
 }
 
+static PyObject *
+long_sizeof(PyLongObject *v)
+{
+	Py_ssize_t res;
+
+	res = sizeof(PyLongObject) + abs(Py_SIZE(v)) * sizeof(digit);
+        if (Py_SIZE(v) != 0)
+		res -=  sizeof(digit);
+	return PyLong_FromSsize_t(res);
+}
+
 #if 0
 static PyObject *
 long_is_finite(PyObject *v)
@@ -3651,6 +3662,8 @@
 	 "Rounding with an ndigits arguments defers to float.__round__."},
 	{"__getnewargs__",	(PyCFunction)long_getnewargs,	METH_NOARGS},
         {"__format__", (PyCFunction)long__format__, METH_VARARGS},
+	{"__sizeof__",	(PyCFunction)long_sizeof, METH_NOARGS,
+	 "Returns size in memory, in bytes"},
 	{NULL,		NULL}		/* sentinel */
 };
 
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 73d501c..6e4ac7a 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -3275,6 +3275,20 @@
         return result;
 }
 
+static PyObject *
+object_sizeof(PyObject *self, PyObject *args)
+{
+	Py_ssize_t res, isize;
+
+	res = 0;
+	isize = self->ob_type->tp_itemsize;
+	if (isize > 0)
+		res = Py_SIZE(self->ob_type) * isize;
+	res += self->ob_type->tp_basicsize;
+
+	return PyLong_FromSsize_t(res);	 
+}
+
 static PyMethodDef object_methods[] = {
 	{"__reduce_ex__", object_reduce_ex, METH_VARARGS,
 	 PyDoc_STR("helper for pickle")},
@@ -3284,6 +3298,8 @@
 	 object_subclasshook_doc},
         {"__format__", object_format, METH_VARARGS,
          PyDoc_STR("default object formatter")},
+        {"__sizeof__", object_sizeof, METH_NOARGS,
+         PyDoc_STR("__sizeof__() -> size of object in memory, in bytes")},
 	{0}
 };