diff --git a/Lib/test/test_fileio.py b/Lib/test/test_fileio.py
index 4e6e1b5..d35549f 100644
--- a/Lib/test/test_fileio.py
+++ b/Lib/test/test_fileio.py
@@ -78,6 +78,9 @@
         self.assertEqual(self.f.readline(None), b"hi\n")
         self.assertEqual(self.f.readlines(None), [b"bye\n", b"abc"])
 
+    def test_reject(self):
+        self.assertRaises(TypeError, self.f.write, "Hello!")
+
     def testRepr(self):
         self.assertEquals(repr(self.f), "<_io.FileIO name=%r mode=%r>"
                                         % (self.f.name, self.f.mode))
@@ -168,7 +171,7 @@
 
     @ClosedFDRaises
     def testErrnoOnClosedWrite(self, f):
-        f.write('a')
+        f.write(b'a')
 
     @ClosedFDRaises
     def testErrnoOnClosedSeek(self, f):
diff --git a/Misc/NEWS b/Misc/NEWS
index 2e12ffe..c5d0e47 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -234,6 +234,8 @@
 Library
 -------
 
+- Don't accept bytes in FileIO.write().
+
 - Removed the functions 'verify' and 'vereq' from Lib/test/support.py.
 
 - Issue #7773: Fix an UnboundLocalError in platform.linux_distribution() when
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 37ddaeb..f02fe8a 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -648,7 +648,7 @@
 	if (!self->writable)
 		return err_mode("writing");
 
-	if (!PyArg_ParseTuple(args, "s*", &pbuf))
+	if (!PyArg_ParseTuple(args, "y*", &pbuf))
 		return NULL;
 
 	if (_PyVerify_fd(self->fd)) {