diff -r fcc61327c86c Lib/test/test_io.py
--- a/Lib/test/test_io.py	Fri Feb 22 08:29:34 2013 +0200
+++ b/Lib/test/test_io.py	Fri Feb 22 17:52:36 2013 +0100
@@ -1371,6 +1371,11 @@
         with self.open(support.TESTFN, "rb") as f:
             self.assertEqual(f.read(), b"123xxx")
 
+    def test_args_error(self):
+        # Issue #17275
+        with self.assertRaisesRegex(TypeError, "BufferedWriter()"):
+            self.tp(io.BytesIO(), 1024, 1024, 1024)
+
 
 class PyBufferedWriterTest(BufferedWriterTest):
     tp = pyio.BufferedWriter
@@ -1740,6 +1745,11 @@
         CBufferedReaderTest.test_garbage_collection(self)
         CBufferedWriterTest.test_garbage_collection(self)
 
+    def test_args_error(self):
+        # Issue #17275
+        with self.assertRaisesRegex(TypeError, "BufferedRandom()"):
+            self.tp(io.BytesIO(), 1024, 1024, 1024)
+
 class PyBufferedRandomTest(BufferedRandomTest):
     tp = pyio.BufferedRandom
 
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 17:52:36 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;
     }