Index: Objects/bytearrayobject.c
===================================================================
--- Objects/bytearrayobject.c	(revision 64448)
+++ Objects/bytearrayobject.c	(working copy)
@@ -57,6 +57,27 @@
     return 1;
 }
 
+static int
+_getbyteasint(PyObject* arg, int *value)
+{
+    long face_value;
+
+    if (PyInt_Check(arg)) {
+        face_value = PyInt_AsLong(arg);
+        if (face_value < 0 || face_value >= 256) {
+            PyErr_SetString(PyExc_ValueError, "byte must be in range(0, 256)");
+            return 0;
+        }
+    }
+    else {
+        PyErr_Format(PyExc_TypeError, "an integer is required");
+        return 0;
+    }
+
+    *value = face_value;
+    return 1;
+}
+
 static Py_ssize_t
 bytes_buffer_getreadbuf(PyByteArrayObject *self, Py_ssize_t index, const void **ptr)
 {
@@ -2636,7 +2657,7 @@
     int value;
     Py_ssize_t n = Py_SIZE(self);
 
-    if (! _getbytevalue(arg, &value))
+    if (! _getbyteasint(arg, &value))
         return NULL;
     if (n == PY_SSIZE_T_MAX) {
         PyErr_SetString(PyExc_OverflowError,