diff --git a/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.mk b/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.mk
index fc9230cb6435..ea38dc9d538b 100644
--- a/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.mk
+++ b/ports/atmel-samd/boards/metro_m0_express/mpconfigboard.mk
@@ -9,3 +9,5 @@ CHIP_FAMILY = samd21
 SPI_FLASH_FILESYSTEM = 1
 EXTERNAL_FLASH_DEVICES = "S25FL216K, GD25Q16C, W25Q16JVxQ"
 LONGINT_IMPL = MPZ
+
+CIRCUITPY_RAINBOWIO = 0
diff --git a/shared/runtime/sys_stdio_mphal.c b/shared/runtime/sys_stdio_mphal.c
index e8e39799d922..3344b19d52e7 100644
--- a/shared/runtime/sys_stdio_mphal.c
+++ b/shared/runtime/sys_stdio_mphal.c
@@ -54,7 +54,7 @@ STATIC const sys_stdio_obj_t stdio_buffer_obj;
 
 STATIC void stdio_obj_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     sys_stdio_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    mp_printf(print, "<io.StringIO %d>", self->fd);
+    mp_printf(print, "<io.%s %d>", mp_obj_get_type_str(self_in), self->fd);
 }
 
 STATIC mp_uint_t stdio_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode) {
@@ -122,7 +122,7 @@ STATIC const mp_stream_p_t stdio_obj_stream_p = {
 
 MP_DEFINE_CONST_OBJ_TYPE(
     stdio_obj_type,
-    MP_QSTR_StringIO,
+    MP_QSTR_TextIOWrapper,
     MP_TYPE_FLAG_ITER_IS_STREAM,
     print, stdio_obj_print,
     protocol, &stdio_obj_stream_p,
diff --git a/tests/basics/sys_stdio.py b/tests/basics/sys_stdio.py
new file mode 100644
index 000000000000..8d746b8b4b25
--- /dev/null
+++ b/tests/basics/sys_stdio.py
@@ -0,0 +1,21 @@
+# Test sys.std* objects.
+
+import sys
+
+try:
+    sys.stdout
+    sys.stdin
+    sys.stderr
+except AttributeError:
+    print("SKIP")
+    raise SystemExit
+
+# CPython is more verbose; no need to match exactly
+
+print('TextIOWrapper' in str(sys.stdout))
+print('TextIOWrapper' in str(sys.stderr))
+print('TextIOWrapper' in str(sys.stdin))
+
+print('TextIOWrapper' in str(type(sys.stdout)))
+print('TextIOWrapper' in str(type(sys.stderr)))
+print('TextIOWrapper' in str(type(sys.stdin)))
diff --git a/tests/basics/sys_stdio_buffer.py b/tests/basics/sys_stdio_buffer.py
new file mode 100644
index 000000000000..ae354ec7fbec
--- /dev/null
+++ b/tests/basics/sys_stdio_buffer.py
@@ -0,0 +1,21 @@
+# Test sys.std*.buffer objects.
+
+import sys
+
+try:
+    sys.stdout.buffer
+    sys.stdin.buffer
+    sys.stderr.buffer
+except AttributeError:
+    print("SKIP")
+    raise SystemExit
+
+# CPython is more verbose; no need to match exactly
+
+print('FileIO' in str(sys.stdout.buffer))
+print('FileIO' in str(sys.stderr.buffer))
+print('FileIO' in str(sys.stdin.buffer))
+
+print('FileIO' in str(type(sys.stdout.buffer)))
+print('FileIO' in str(type(sys.stderr.buffer)))
+print('FileIO' in str(type(sys.stdin.buffer)))
diff --git a/tests/basics/sys_stdio_buffer.py.exp b/tests/basics/sys_stdio_buffer.py.exp
new file mode 100644
index 000000000000..681c7ec9e840
--- /dev/null
+++ b/tests/basics/sys_stdio_buffer.py.exp
@@ -0,0 +1,6 @@
+True
+True
+True
+True
+True
+True