diff -r fcc61327c86c Modules/_io/bufferedio.c
--- a/Modules/_io/bufferedio.c	Fri Feb 22 08:29:34 2013 +0200
+++ b/Modules/_io/bufferedio.c	Fri Feb 22 12:57:45 2013 +0100
@@ -1822,7 +1822,7 @@
     self->ok = 0;
     self->detached = 0;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedReader", kwlist,
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedWriter", kwlist,
                                      &raw, &buffer_size)) {
         return -1;
     }
@@ -2451,7 +2451,7 @@
     self->ok = 0;
     self->detached = 0;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedReader", kwlist,
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|n:BufferedRandom", kwlist,
                                      &raw, &buffer_size)) {
         return -1;
     }