diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 2361636..2e5d7ac 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -388,6 +388,11 @@ fileio_init(PyObject *oself, PyObject *args, PyObject *kwds)
             goto error;
     }
 
+#if defined(MS_WINDOWS) || defined(__CYGWIN__)
+    /* don't translate newlines (\r\n <=> \n) */
+    _setmode(self->fd, O_BINARY);
+#endif
+
     if (PyObject_SetAttrString((PyObject *)self, "name", nameobj) < 0)
         goto error;
 
diff --git a/Modules/main.c b/Modules/main.c
index 93d093d..0b656e5 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -527,11 +527,14 @@ Py_Main(int argc, wchar_t **argv)
 
     stdin_is_interactive = Py_FdIsInteractive(stdin, (char *)0);
 
-    if (Py_UnbufferedStdioFlag) {
 #if defined(MS_WINDOWS) || defined(__CYGWIN__)
-        _setmode(fileno(stdin), O_BINARY);
-        _setmode(fileno(stdout), O_BINARY);
+    /* don't translate newlines (\r\n <=> \n) */
+    _setmode(fileno(stdin), O_BINARY);
+    _setmode(fileno(stdout), O_BINARY);
+    _setmode(fileno(stderr), O_BINARY);
 #endif
+
+    if (Py_UnbufferedStdioFlag) {
 #ifdef HAVE_SETVBUF
         setvbuf(stdin,  (char *)NULL, _IONBF, BUFSIZ);
         setvbuf(stdout, (char *)NULL, _IONBF, BUFSIZ);