diff -r ef8ee7a90e84 Modules/arraymodule.c
--- a/Modules/arraymodule.c	Sun Jun 13 13:07:57 2010 +0200
+++ b/Modules/arraymodule.c	Sun Jun 13 21:36:44 2010 +0200
@@ -1335,11 +1335,19 @@
 static PyObject *
 array_fromstring(arrayobject *self, PyObject *args)
 {
+    Py_buffer buffer;
     char *str;
     Py_ssize_t n;
     int itemsize = self->ob_descr->itemsize;
-    if (!PyArg_ParseTuple(args, "s#:fromstring", &str, &n))
+    if (!PyArg_ParseTuple(args, "s*:fromstring", &buffer))
         return NULL;
+    if (buffer.itemsize != 1) {
+        PyBuffer_Release(&buffer);
+        PyErr_SetString(PyExc_TypeError, "string/buffer of bytes required.");
+        return NULL;
+    }
+    str = buffer.buf;
+    n = buffer.len;
     if (n % itemsize != 0) {
         PyErr_SetString(PyExc_ValueError,
                    "string length not a multiple of item size");
@@ -1357,6 +1365,7 @@
         memcpy(self->ob_item + old_size * itemsize,
             str, n * itemsize);
     }
+    PyBuffer_Release(&buffer);
     Py_INCREF(Py_None);
     return Py_None;
 }